The Algerian Army on Thursday surrounded a natural gas complex where Islamist militants have taken dozens of people as hostage. The rare attack took place on Wednesday night and was seen as an unexpected fallout of the French intervention in Mali.
The militant group, which claimed responsibility for the attack in which two foreigners were killed, said it was holding 41 foreign nationals, including seven Americans, as hostage. The militants attacked one of oil-rich Algeria's energy facilities, 800 miles from the capital of Algiers and 1,000 miles (1,600 kilometres) from the coast.
These are key developments of the hostage drama so far:
*Death toll from terrorist seige over 80
The death toll from the terrorist siege at a natural gas plant in the Sahara climbed past 80 on Sunday as Algerian forces searching the refinery for explosives found dozens more bodies, many so badly disfigured it was unclear whether they were hostages or militants, a security official said.
Algerian special forces stormed the plant on Saturday to end the four-day siege, moving in to thwart what government officials said was a plot by the Islamic extremists to blow up the complex and kill all their captives with mines sown throughout the site.
In a statement, the Masked Brigade, the group that claimed to have masterminded the takeover, warned of more such attacks against any country backing France's military intervention in neighboring Mali, where the French are trying to stop an advance by Islamic extremists.
"We stress to our Muslim brothers the necessity to stay away from all the Western companies and complexes for their own safety, and especially the French ones," the statement said.
Algeria said after Saturday's assault by government forces that at least 32 extremists and 23 hostages were killed. On Sunday, Algerian bomb squads sent in to blow up or defuse the explosives found 25 more bodies, said the security official, who spoke on condition of anonymity because of the sensitivity of the situation.
"These bodies are difficult to identify. They could be the bodies of foreign hostages or Algerians or terrorists," the official said.
In addition, a wounded Romanian who had been evacuated died, raising the overall death toll to at least 81.
*West worried over deadly hostage
An AFP report says that western governments voiced alarm over the fate of dozens of foreigners seized by Islamists at a gas plant in the Algerian desert after several hostages were killed in a dramatic rescue operation.
*Algeria desert siege ends, at least 30 dead
Algerian forces stormed a desert gas complex to free hundreds of hostages but 30, including several Westerners, were killed in the assault along with at least 11 of their Islamist captors, an Algerian security source told Reuters.
*30 hostages killed
Thirty hostages, including at least seven foreigners, were killed on Thursday when Algerian forces stormed a desert gas plant seized by Islamist militants, an Algerian security source said.
*Algeria mulls international force for hostages
An Algerian security official says the government is in talks with the United States and France over whether an international force can help in a standoff with Islamist militants who have taken dozens of foreigners hostage in a natural gas complex deep in the Sahara.
*Some Algeria hostages made to wear explosives
Islamist militants in Algeria forced some of the hostages to wear belts strapped with explosives, French television said on Thursday, quoting one of the hostages. France 24 said the man also told the channel during a telephone call late on Wednesday that the hostage-takers were heavily armed and had threatened to blow up the natural gas facility if the Algerian army tried to free the hostages.
*Briton, Norwegian killed
Briton and a Norwegian were killed on Wednesday in an attack targeting an oil facility in Algeria's central province of Illizi, the official APS news agency reported. The Norwegian national, who was the first victim in the attack, worked with British Petroleum (BP), Xinhua reported citing Norway's Bergens Tidende newspaper.
*Briton among two hostages killed
British newspaper Somerset Gazette reported on Thursday that two of the hostages taken by Algerian Islamists on a BP gas facility in eastern Algeria have been killed, one of them was British.
*US confirms two citizens among hostages
The United States said on Wednesday that US citizens were among the hostages taken when the militants raided the gas facility. State Department spokeswoman Victoria Nuland said that Clinton had spoken with both Algerian Prime Minister Abdelmalek Sellal and the US ambassador in Algeria on Thursday, and that US officials were in contact with the security office of British Petroleum, which operates the gas field together with Norway's Statoil and Algeria's state company Sonatrach.
*The reason behind the hostage crisis
The attack, which Algeria said was led by a veteran, Afghan-trained holy warrior-cum-smuggler dubbed 'The Uncatchable' by French intelligence, came just as French ground troops in Mali launched their first assault after six days of air strikes.
French fighter jets have been pounding an Islamist rebel stronghold deep in northern Mali since 13 January as Paris poured more troops into the capital Bamako, awaiting a West African force to dislodge al Qaeda-linked insurgents from the country's north.
Many fear the area could act as a base for attacks on the West and for links with al Qaeda in Yemen, Somalia and North Africa.
Deep inside caves, in remote desert bases, in the escarpments and cliff faces of northern Mali, Islamic fighters burrowed into the earth, erecting a formidable set of defenses to protect what has essentially become Al Qaeda's new country. They have used the bulldozers, earth movers and Caterpillar machines left behind by fleeing construction crews to dig what residents and local officials describe as an elaborate network of tunnels, trenches, shafts and ramparts.
Northern Mali became the biggest territory held by Al Qaeda and its allies. And as the world hesitated, delaying a military intervention, the extremists who seized control of the area in 2012 prepared for a war they boast will be worse than the decade-old struggle in Afghanistan.