British police have identified the person responsible for the terror attack near Parliament as 52-year-old Khalid Masood.
The police say in a statement on Thursday that Masood was born in southeastern England and was most recently living in the West Midlands, in central England.
Police say Masood, who had a number of aliases, wasn't the subject of any current investigation and that "there was no prior intelligence about his intent to mount a terrorist attack."
He had been arrested previously for assault, possession of offensive weapons and public order offenses.
His first conviction was in November 1983 for criminal damage and his last was in December 2003 for possession of a knife.
Car rental company Enterprise has confirmed that the car used in the terror attack in London this week was owned by them and rented in Birmingham.
The company said in a statement on Thursday that the car "used in the tragic attack in London yesterday afternoon was one of ours."
The company says an employee identified the vehicle after seeing the license plate in an online image. The company checked and immediately contacted authorities.
It says it is cooperating fully.
The company says "our thoughts are very much with the victims of this terrible tragedy."
Armed police have arrested eight people in raids linked to the rampage that left three people dead and sowed panic in the heart of London.
The Islamic State group said it was responsible, according to the Amaq propaganda agency linked to the jihadist organisation.
"The perpetrator of yesterday's attack in front of the British parliament was a soldier of the Islamic State and the operation was carried out in response to calls to target coalition countries," Amaq said citing a "security source."
Defiant British lawmakers returned to "business as usual" in the surreal silence of an area of central London normally thronged with tourists.
Twenty-nine people were treated in hospital, including seven in critical condition, some with "catastrophic" injuries. Among them were French school children and foreign tourists.
The attacker mowed down pedestrians with a car on Westminster bridge, killing two, and then jumped out and stabbed to death a police officer guarding parliament before being shot dead.
The carnage was unleashed on the same day Brussels was marking the anniversary of Islamic State group bombings that killed 32 people.
Hundreds of extra police were on patrol in London as officers worked around the clock to piece together what happened in the deadliest attack in Britain since four suicide bombers killed 52 people on the capital's transport system in July 2005.
Europe has been on high alert after a wave of deadly jihadist assaults over the past two years.
Britain's top anti-terror officer Mark Rowley said that police had arrested eight people in raids on six houses in London, the central city of Birmingham and elsewhere.
"It is still our belief... that this attacker acted alone yesterday and was inspired by international terrorism," he said.
Defence Secretary Michael Fallon told BBC radio the working assumption was that the attack was linked to "Islamic terrorism in some form".
The British flag over parliament flew at half-mast in a sign of mourning while forensic officers in white suits carried out a fingertip search of the courtyard outside where 48-year-old policeman Keith Palmer was stabbed to death.
Police officers lined up outside their new headquarters nearby for a minute's silence in front of the eternal flame to officers who have given their lives in service.
Queen Elizabeth II was due to open the building formally on Thursday but postponed the visit.
"My thoughts, prayers, and deepest sympathy are with all those who have been affected by yesterday's awful violence," she said, in a statement expressing her "enduring admiration" for the police.
London Mayor Sadiq Khan called a candlelit vigil on Trafalgar Square later Thursday.
Among those in parliament was Foreign Office minister Tobias Ellwood, whose face was left smeared with blood after giving first aid to the fatally wounded police officer.
US President Donald Trump and French President Francois Hollande both spoke to May and Chancellor Angela Merkel said Germany stood with Britons "against all forms of terrorism".
Britain's last terror attack was the 2016 assassination of MP Jo Cox by a pro-Nazi sympathiser in her constituency in northern England shortly before the vote to leave the European Union.
With inputs from agencies
Updated Date: Mar 23, 2017 21:35 PM