A man detained on suspicion of carrying out a terrorist attack outside Britain's parliament is Salih Khater, a British citizen of Sudanese origin, a European security source told Reuters on Wednesday.
Police believe a car was deliberately driven into pedestrians and cyclists, injuring three people, before ramming a security barrier outside parliament on Tuesday morning.
The 29-year-old driver was arrested by armed officers at the scene moments later. He is currently being questioned on suspicion of preparing acts of terrorism and on Wednesday was further arrested on suspicion of attempted murder, although police have said he is not co-operating with detectives.
The security source told Reuters that Khater was from Birmingham, central England, and was not known to security services before Tuesday.
A spokesman for nearby Coventry University told the Daily Telegraph newspaper Khater had studied accountancy from September 2017 until May 2018 but failed his first year course and lost his place.
Speaking shortly after the incident, Britain's counter-terrorism police chief said that given the iconic location and the method used, it appeared the incident was "a deliberate act" and was therefore being treated as a terrorist incident.
The incident took place shortly after 7.30 am local time on Tuesday on the main road between the Houses of Parliament and Westminster Abbey.
A silver Ford Fiesta sped down the street, striking a group of cyclists before smashing into a concrete barrier designed to stop car bombs.
“He made no attempt to slow down as he hit the cyclists,” said Robert Nicholson, 36, who was on his way to work. “There was a bike flying into the air.”
Video captured by Euronews correspondent Vincent McAviney showed the light-coloured vehicle, its bonnet crumpled in the road. A man was dragged from the car by police and arrested.
Police moved bystanders away from the scene and closed roads in the area.
Ewelina Ochab witnessed the incident and told Euronews: “I was walking on the other side of the pavement from where the incident occurred. I heard some noise, and someone screamed. I turned around and I saw a silver car driving from the crossing — very fast and close to the railings, maybe even on the pavement.
"The car drove at speed into the barriers outside the House of Lords. There was a loud bang from the collision and a bit of smoke.
"The driver did not get out. The guards started screaming at people to move away. One elderly man rushed me to hide behind a monument, just in case. The police arrived very quickly."
Politicians and Londoners paid tribute to the work of the emergency services.
British Prime Minister Theresa May, who is on holiday during parliament's summer recess, said her thoughts were with the injured people. "The threat to the United Kingdom from terrorism remains severe. I would urge the public to remain vigilant," she said.
"All Londoners, like me, utterly condemn all acts of terrorism on our city," London's Mayor Sadiq Khan said on Twitter.
US President Donald Trump, who has previously spoken out about security issues in London, said on Twitter: "These animals are crazy and must be dealt with through toughness and strength."
Britain is on its second-highest threat level of "severe", meaning an attack is considered highly likely and the authorities say a dozen Islamist plots had been foiled since the attack in Westminster in March 2017.
[This article was corrected on 14/08/2018 to show the vehicle was a Ford Fiesta.]