09.07 am: Investigators identify suspect via security video
Investigators have spotted a Boston Marathon bombing suspect from security video taken before two blasts ripped through central Boston on Monday, a law enforcement source said on Wednesday, in what is potentially the biggest break in the case yet.
No arrests had been made, and the suspect in the video had not been identified by name, two government officials said.
Police considered making an appeal to the public for more information at a news conference, a government source said, but the FBI canceled that news conference after delaying it several times, Boston police said.
No one has claimed responsibility for the attack.
“Whether it’s homegrown or foreign, we just don’t know yet. And so I’m not going to contribute to any speculation on that,” said US secretary of state John Kerry. “It’s just hard to believe that a Patriots’ Day holiday, which is normally such time of festivities, turned into bloody mayhem.”
-- Updates closed for the day--
11.54 am: State newspaper identifies Chinese victim of Boston blasts
A state-run Chinese newspaper says the third person killed in the Boston Marathon bombings is a Chinese graduate student at Boston University originally from China's northeastern city of Shenyang.
The Shenyang Evening News reported Wednesday on its official Twitter-like microblog account that the victim is named Lu Lingzi. An editor at the newspaper says that Lu's father confirmed his daughter's death when reporters visited the family home.
The Chinese Foreign Ministry and Consulate General in New York are not releasing the victim's name at the request of the family. But on Tuesday, Boston media quoted a Chinese Consulate General official as saying Chinese national Lu Lingzi was missing in the wake of the bombings that killed three and wounded more than 170 people.
10.25 am: President Obama to visit Boston tomorrow
US President Barack Obama will travel to Boston tomorrow to attend an interfaith service dedicated to the victims of two bomb blasts in the city during the annual marathon.
"On Thursday (tomorrow) morning, the President will travel to Boston to speak at an interfaith service dedicated to those who were gravely wounded or killed in Monday's bombing near the finish line of the Boston Marathon," the White House said in a statement.
The President's earlier scheduled visit to University of Kansas on Friday has been cancelled, it added.
9. 57 am: Boston blast scene pictures show remains of explosive device
Boston Marathon bomb scene pictures taken by investigators and released on Tuesday show the remains of an explosive device including twisted pieces of a metal container, wires, a battery and what appears to be a small circuit board.
One picture shows a few inches of charred wire attached to a small box, and another depicts a half-inch (1.3 cm) nail and a zipper head stained with blood. Another shows a Tenergy brand battery attached to black and red wires through a broken plastic cap.
Several photos show a twisted metal lid with bolts.
A US government official, who declined to be identified, made the pictures available to Reuters.
It was not immediately clear what fresh light the photographs shed on the attack. The official said they were taken by Boston's Joint Terrorism Task Force at the scene where two bombs killed three people and wounded 176 on Monday at the finish line of the Boston Marathon.
Earlier Tuesday, FBI Special Agent in Charge Richard DesLauriers told a news conference that evidence recovered from the crime scene on Tuesday morning would be used to reconstruct the device or devices at the Federal Bureau of Investigation laboratory in Quantico, Virginia.
17 April, 20138. 20 am: Pressure cooker bombs were used in Boston blasts
The explosives that killed three people and injured more than 170 during the Boston Marathon on Monday were most likely rudimentary devices made from ordinary kitchen pressure cookers, except they were rigged to shoot sharp bits of shrapnel into anyone within reach of their blast and maim them severely, law enforcement officials said on Tuesday.
The pressure cookers were filled with nails, ball bearings and black powder, and the devices were triggered by "kitchen-type" egg timers, one official said.
The resulting explosions sent metal tearing through skin and muscle, destroying the lower limbs of some victims who had only shreds of tissue holding parts of their legs together when they arrived at the emergency room of Massachusetts General Hospital, doctors there said.
Law enforcement officials said the devices were probably hidden inside dark nylon duffel bags or backpacks and left on the street or sidewalk near the finish line.
Updates closed for the night.
9. 45 pm: Boston explosions investigated as terrorism, says Obama
President Barack Obama said that the explosions at the Boston Marathon are being investigated as an act of terror, although authorities still do not know who is responsible.
He called the bombing "a heinous and cowardly act" used to target innocent civilians.
Obama spoke to reporters at the White House after a briefing by his national security team.
Three people were killed, including an 8-year-old boy, and more than 170 were wounded in Monday's bombing at the famous marathon's finish line. - AP
7.20 pm: It's been a bad day but Boston will overcome
Speaking at a press conference, Governor Deval Patrick said no further expolsive material was found after the two blasts that took place. He further said that 150 people were injured in the blast/
"There are no additional threats, 30 forensic specialists at the blast site as well as trained canines at site."
Boston Mayor Thomas Menino termed Tuesday as a 'bad day' for Boston. "It's a bad day but I think we will pull together.. Let us all say Boston will overcome."
3. 10 pm: FBI gets early leads, makes progress in Boston blasts investigation
A law enforcement official said that the probe into Boston bombings has got some active leads with good progress in forensic investigation.
FBI special agent Rick DesLauriers said, "It is a criminal investigation that is a potential terrorist investigation."
The FBI has been examining surveillance cameras in the area and issuing subpoenas for records from cell towers in the area to isolate and trace calls from around Copley Square at the time of the blasts, according to the official.
Investigators have warned police officers to be on the lookout for a "darker-skinned or black male" with a possible foreign accent in connection with the Marathon bombing, CNN said citing a law enforcement advisory.
The man was seen with a black backpack and sweatshirt and was trying to get into a restricted area about five minutes before the first explosion, the lookout notice states.
12. 40 pm: Pakistan Taliban deny role in Boston Marathon blasts
The Pakistani Taliban, which claimed the 2010 Times Square bomb plot, today denied anything to do with explosions that killed three people and wounded more than 100 in Boston.
"We believe in attacking US and its allies but we are not involved in this attack," Tehreek-e-Taliban Pakistan (TTP) spokesman Ehsanullah Ehsan told AFP.
"We have no connection to this bombing but we will continue to target them wherever possible," Ehsan added.
Monday's explosions at the Boston Marathon, one of America's top sporting events, forced cities from New York to Los Angeles to go on high alert and conjured up memories of the 11 September, 2001 attacks.
11. 25 pm: UN chief calls Boston Marathon blasts 'senseless violence'
UN Secretary General Ban Ki-moon has condemned the bombing at the Boston Marathon as "senseless violence".
Speaking at a ceremony at UN Headquarters commemorating the 19th anniversary of the Rwanda genocide Monday, Ban said the bombing "is all the more appalling for taking place at an event renowned for bringing people together from around the world in a spirit of sportsmanship and harmony", reported Xinhua.
"For now I just wanted to say that my thoughts are with everyone in Boston," Ban said, expressing his deepest condolences to the families of the victims and wishing those wounded a speedy recovery.
11. 05 pm: PM writes to Obama, expresses shock and sadness over Boston attack
India's Prime Minister Manmohan Singh wrote to the United States President Barack Obama today condemning the attacks at the Boston Marathon.
Singh said that India is ready to offer its full support in combating terrorism.
PM writes to US President: The people of India join me in condemning the attack in strongest terms.
— Dr Manmohan Singh (@PMOIndia) April 16, 2013
PM: We stand in solidarity and sympathy with the bereaved families, the injured and the people of the United States.
— Dr Manmohan Singh (@PMOIndia) April 16, 2013
PM: This senseless and cowardly act of violence has struck a city that has long stood as a symbol of openness, learning and enterprise.
— Dr Manmohan Singh (@PMOIndia) April 16, 2013
10. 40 am: Indian-Americans, Muslims condemn Boston blasts
Indian-Americans and the Muslim community in the US joined their shocked countrymen in condemning the Boston bomb blasts that killed three persons and injured over 140.
"We hope that the perpetrators will be caught promptly, unlike after the Atlanta Olympics bombing, and punished to the fullest extent of the law," said Indian American Dr Shaik Ubaid, who is co-chair of the New York chapter of the Muslim Peace Coalition.
"Indian-American community strongly condemned the bomb blast in Boston today. Terrorism has no religion, race, or nationality. Standing against terror should unite us all. Whoever the culprit, no religion justifies this act of violence. We must remain united against extremism" the North American Punjabi Association (NAPA) said in a statement.
The Muslim Public Affairs Council also issued a statement condemning the blast. "This is a horrible crime, and we call on all of us as Americans to work together to bring those responsible to justice," it said.
To attack people on what is supposed to be a day of jubilation is criminal and inexcusable, the council said.
"This is a time for us to show resilience and calmness, as we come together to help the American public recover from this heinous act," said Salam Al-Marayati, MPAC president. The Council on American-Islamic Relations (CAIR), the largest Muslim civil rights and advocacy organisation, also condemned the bomb attacks.
"American Muslims, like Americans of all backgrounds, condemn in the strongest possible terms today's cowardly bomb attack on participants and spectators of the Boston Marathon," said its national executive director Nihad Awad.
"We urge people of all faiths to pray for the victims and their loved ones and for the speedy recovery of those injured. We also call for the swift apprehension and punishment of the perpetrators," he said.
10. 30 am: How the US media reacted to the Boston Marathon blasts
The American media reacted with horror to the twin blasts at the Boston Marathon that once again brought the nation face to face with the threat of terrorism and showed "how vulnerable the US homeland still is".
"In Boston, explosions transform a scene of celebration into one of tragedy," said the Washington Post in an editorial noting, "In the weeks and months after the 2001 terrorist attacks, every iconic sports event became an occasion for anxiety."
"The simple joy of a 26.2-mile run was shattered on Monday," wrote the New York Times in an editorial titled "Bombs at the Marathon."
Calling a marathon as "the most unifying of sporting events," the influential daily expressed confidence "the marathon will be back next year, no matter how much security is required, and the crowds should yell twice as loudly."
"No act of terrorism is strong enough to shatter a tradition that belongs to American history," it said.
The Wall Street Journal in a similar vein said "Terror in Boston" was "A reminder of how vulnerable the US homeland still is."
"The Boston bombing is above all a reminder of the continuing need for heightened defences against terror threats," the Journal wrote.
"As the years since 9/11 without a successful homeland attack increased, the temptation was to forget how vulnerable the US is, and to conclude that the worst is over."
"Boston shows that the terror threat continues to be real, and that the price of even a peaceful marathon is constant vigilance," it concluded.
Here is a list of some of the worst bombings in the US dating to the 1800s, including some famous attempts that failed.
9. 50 am: "Many victims have lost their limbs," says Massachusetts General Hospital surgeon
A surgeon at Massachusetts General Hospital says they have treated 29 victims from the attack. He says eight people are in a critical condition, some victims have lost limbs and many have "small metal debris" or shrapnel injuries. The oldest patient is 71-years-old.
9.40 am: Police searches apartment in Boston suburb for clues
As the FBI took charge of the investigation, authorities shed no light on a motive or who may have carried out the bombings, and police said they had no suspects in custody. Officials in Washington said there was no immediate claim of responsibility.
WBZ-TV reported late Monday that law enforcement officers were searching an apartment in the Boston suburb of Revere. Massachusetts State Police confirmed that a search warrant related to the investigation into the explosions was served Monday night in Revere but provided no further details.
9. 30 am: Flights banned over blast site, mobile networks disrupted
Media reports said the federal investigating agencies and law enforcement bodies have increased their check on all outgoing international flights, indicating that they might be looking into the possibility of a foreign link to the attack that sent shock waves to the entire nation.
The heavy volume of mobile phone calls around downtown Boston following explosions at the Boston Marathon has clogged cell service, blocking many from getting through to people at the scene, reportedThe Boston Globe.
In a statement, AT&T said: “As we coordinate with local officials, customers in the area may be experiencing issues with wireless voice and data service due to a spike of network activity and related congestion. We recommend customers use text messaging for emergencies. We also advise customers to keep non-emergency calls to a minimum. To help, our temporary Wi-Fi turned up for the Boston Marathon will remain on for an extended timeframe.”
9. 20 am: What India can learn from the Boston blasts
There are many lessons that India can learn from the Boston blasts. The most important lesson being how they got their emergency-service providers right.
The difference is that first-responders in the United States, whether police or ambulance services, rehearse well laid-down drills regularly. In India, under-staffed, under-trained and under-paid first-response services don’t. The difference shows. Read Praveen Swami's piece on the 3 lessons for India here.
Meanwhile, a Times journalist noted that many people ran towards the victims at the blast site to help them.
As others have observed: nearly as many people ran toward the Boston blasts to help as ran away from them. There is hope for humanity.
— Jeffrey Kluger (@jeffreykluger) April 15, 2013
8. 55 am: Navy sends bomb-disposal units to Boston
The Navy has sent one of its bomb-disposal units to Boston to assist local authorities as needed in the aftermath of the two explosions near the Boston Marathon's finish line. The blasts killed three and injured more than 140.
The three-member explosive ordnance disposal team based at Naval Station Newport, Rhode Island, was sent to Massachusetts after state officials asked for help. Authorities are investigating the bombings and also are checking other bags and packages that may have been left unattended as terrified crowds races away from the chaos Monday.
The Pentagon said no other active duty military personnel had yet been sent to the scene, although state National Guard troops were there. The Defense Department has not raised the threat level across the nation's military installations.
8. 40 am: According to the latest reports, the blasts have killed at least 3, injured over 144. Over 15 people were critically injured.
8. 15 am: Security beefed up in key US cities
Several mega cities in the US, including New York, Los Angeles, Chicago and Washington, have been put on alert after two explosions in Boston that left two dead, besides injuring many.
Security in and around all critical establishments has been tightened and according to a <em>CNN</em> report, flight movements over the bomb blast site in Boston have been banned.
Security of the White House was stepped up soon after the bomb blasts in Boston.
Here's a video of the blasts:
"Out of an abundance of caution, we have expanded our security perimeter at the White House complex. It is not unusual to expand or contract these security perimeters," Secret Service spokesman Edwin Donovan said.
8. 05 am: Boston tragedy delays immigration bill
A group of eight lawmakers, equally divided between Republicans and Democrats, planned to formally introduce the bill Tuesday, although a press event with activists, business leaders and religious groups was delayed until later in the week after the bombing at the Boston marathon.
Sens. Chuck Schumer, a New York Democrat, and John McCain, an Arizona Republican, planned to meet with President Barack Obama Tuesday to discuss the legislation with him, according to a person with knowledge of the plan who spoke on condition of anonymity to discuss the private meeting. Immigration legislation is a top second-term priority for the president.
The legislation would be the culmination of months of closed-door meetings among a so-called Gang of Eight senators, including McCain, Schumer and Republican Sen. Marco Rubio of Florida.
Their legislation aims to strike a balance between enforcement provisions sought by Republicans, and Democratic priorities, including making citizenship widely accessible to those illegally in the U.S.
8.00 am: Eight-year-old among dead in Boston blasts
A person familiar with the situation tells The Associated Press that an 8-year-old-boy has been killed in the explosions near the finish line of the Boston Marathon.
Police say three people were killed in the blasts. They provided no details, but someone who spoke to a friend of the family and spoke to the AP on condition of anonymity to protect the family's privacy confirmed that an 8-year-old boy was among the dead.
The person said the boy's mother and sister were also injured as they waited for his father to finish the race.
The explosions injured at least 144 people, 17 critically.
7. 45 am: Despite Boston Marathon blasts, London Marathon to go ahead
Race organisers said the London Marathon would go ahead on Sunday despite the death of at least two people in explosions near the finish line of the Boston Marathon, but police said they would review security plans.
British Prime Minister David Cameron wrote on Twitter that footage from the blasts was "shocking and horrific", and said that his thoughts were with those affected.
The harrowing scenes of injured spectators quickly prompted fears of a similar incident at the London race.
"We will not be cancelling, what we are doing, we are reviewing," London Marathon Chief Executive Nick Bitel told BBC Radio 5 Live.
"You look at what has occurred, if there are steps we can take to increase security and all sorts of measures one could deploy.
7.00 am: Five undetonated explosives found around Boston
The scale of Monday’s disaster could have been worse. According to a Wall Street Journal report, counter-terrorism officials have found what they believe to be five additional, undetonated explosive devices around the Boston area.
The devices—which are in addition to the two that exploded near the finish line of the marathon—were discovered over the course of a frantic inspection of suspicious packages, many of them abandoned as pedestrians, runners, and others scrambled away from crowded public streets. Each had been rendered inoperative or was in the process of being rendered inoperative, the officials said.
5.00 am: Twin blasts at Boston Marathon kill 3, injures many
Two bombs exploded in the packed streets near the finish line of the Boston Marathon on Monday, killing three people and injuring more than 130 in a terrifying scene of shattered glass, bloodstained pavement and severed limbs at the world's oldest and most prestigious marathon, authorities said.
A senior U.S. intelligence official said two other bombs were found near the end of the 26.2-mile (42-kilometer) course.
The fiery twin blasts took place almost simultaneously and about 100 yards (meters) apart, knocking spectators and at least one runner off their feet, shattering windows and sending dense plumes of smoke rising over the street and through the fluttering national flags lining the course.
When the second bomb went off, the spectators' cheers turned to screams. As sirens blared, emergency workers and National Guardsmen assigned to the race for crowd control began climbing over and tearing down temporary fences to get to the blast site.
A pool of blood formed, and huge shards were missing from window panes as high as three stories.
"They just started bringing people in with no limbs," said runner Tim Davey, of Virginia. He said he and his wife, Lisa, tried to keep their children's eyes shielded from the gruesome scene inside a medical tent that had been set up to care for fatigued runners, but "they saw a lot."
Boston police said three people were killed. Hospitals reported at least 134 injured, at least 15 of them critically. The injuries ranged from cuts and bruises to amputations. Many victims suffered lower leg injuries and shrapnel wounds. Some suffered ruptured eardrums.
Some 23,000 runners took part in the race, which attracts more than 500,000 spectators and winds up in the heart of central Boston, near the landmark Prudential Center and the Boston Public Library. It is held on Patriots Day, a Massachusetts state holiday which commemorates the first battles of the American Revolution in 1775.
Obama pledges help
At the White House, President Barack Obama vowed that those responsible will "feel the full weight of justice."
"Any responsible individuals, any responsible groups, will feel the full weight of justice," President Barack Obama vowed.
“We still do not know who did this or why, and people shouldn’t jump to conclusions before we have all the facts,” Obama said. “But make no mistake — we will get to the bottom of this.”
The president declined to answer a question on whether the attacks were acts of terrorism.
A White House official speaking on condition of anonymity because the investigation was still unfolding said the attack was being treated as an act of terrorism.
Authorities shed no light on a motive or who may have carried out the bombings, and police said they had no suspects in custody. Authorities in Washington said there was no immediate claim of responsibility. The FBI took charge of the investigation.
Boston Police Commissioner Edward Davis asked people to stay indoors or go back to their hotel rooms and avoid crowds as bomb squads methodically checked parcels and bags left along the race route. He said investigators didn't know precisely where the bombs were planted or whether they were hidden in mailboxes or trash cans.
He said authorities had received "no specific intelligence that anything was going to happen" at the race.
The Federal Aviation Administration barred low-flying aircraft from within 3.5 miles (5.6 kilometers) of the site.
Obama was briefed on the explosions by Homeland Security adviser Lisa Monaco. Obama also told Boston Mayor Tom Menino and Gov. Deval Patrick that his administration would provide whatever support was needed, the White House said.
"We still don't know who did this or why," Obama said, adding, "Make no mistake: We will get to the bottom of this."
The Federal Aviation Administration created a no-fly zone over the site of the explosions, and briefly ordered flights bound for Boston's Logan International Airport held on the ground at airports around the U.S.
A few miles (kilometers) away from the finish line and around the same time, a fire broke out at the John F. Kennedy presidential library. The police commissioner said it may have been caused by an incendiary device but didn't appear to be related to the bombings.
The first loud explosion occurred on the north side of Boylston Street, just before the photo bridge that marks the finish line. The second explosion could be heard a few seconds later.
They occurred about four hours into the race and two hours after the men's winner crossed the line. By that point, more than 17,000 of the runners had finished the race, but thousands of others were farther back along the course.
The four-hour mark is typically a highly crowded time near the finish line — both because of the slow-but-steady recreational runners likely to be completing the race and because of all the relatives and friends clustered around to cheer them on.
Runners in the medical tent for treatment of dehydration or other race-related ills were pushed out to make room for victims of the bombing.
A senior U.S. intelligence official said the two other explosive devices found nearby were being dismantled. The official spoke on condition of anonymity because he was not authorized to discuss the findings publicly.
At Congress, members of intelligence committees said they expected to be briefed on the attack on Tuesday.
A woman who was near the second bomb, Brighid Wall, 35, said that when it exploded, runners and spectators froze, unsure of what to do. Her husband threw their children to the ground, lay on top of them and another man lay on top of them and said, "Don't get up, don't get up."
She said she saw six to eight people bleeding profusely, including one man who was kneeling, dazed, with blood coming down his head. Another person was on the ground covered in blood and not moving.
"My ears are zinging. Their ears are zinging. It was so forceful. It knocked us to the ground."
Competitors and race volunteers were crying as they fled the chaos. Authorities went onto the course to carry away the injured while race stragglers were rerouted away from the smoking site.
Roupen Bastajian, a 35-year-old state police officer from the neighboring state of Rhode Island, had just finished the race when they put the heat blanket wrap on him and he heard the blasts.
"I started running toward the blast. And there were people all over the floor," he said. "We started grabbing tourniquets and started tying legs. A lot of people amputated. ... At least 25 to 30 people have at least one leg missing, or an ankle missing, or two legs missing."
At Massachusetts General Hospital, said Alisdair Conn, chief of emergency services: "This is something I've never seen in my 25 years here ... this amount of carnage in the civilian population. This is what we expect from war."
The Boston Marathon honored the victims of the December shooting in Newtown, Connecticut, with a special mile marker in Monday's race.
Boston Athletic Association president Joanne Flaminio previously said there was "special significance" to the fact that the race is 26.2 miles long and 26 people died at Sandy Hook Elementary school.
Cities worldwide stepped up security following the explosions.
In Britain, police said they were reviewing security plans for Sunday's London Marathon, the next major international marathon. Thousands of people compete in the London Marathon every year, thronging the city's streets. London is also considered a top target for international terrorists.
A London Metropolitan Police spokesman confirmed Monday that police are working with marathon officials to review security plans for Sunday's event. The London race's chief executive, Nick Bitel, expressed shock and sadness about the situation in Boston, saying "it is a very sad day for athletics and for our friends in marathon running."
In New York City, police spokesman Paul Browne said that critical response teams are deployed around the city. Officials were stepping up security at hotels and other prominent locations.
Spectator Cherie Falgoust was waiting for her husband, who was running the race.
"I was expecting my husband any minute," she said. "I don't know what this building is ... it just blew. Just a big bomb, a loud boom, and then glass everywhere. Something hit my head. I don't know what it was. I just ducked."