Salih Khater has been named as the man who rammed a car into security barriers outside the Houses of Parliament, a European security source told Reuters on Wednesday.
What do we know about him?
Khater, 29, is a British citizen from Birmingham with Sudanese origin, authorities said.
He was detained at the scene on suspicion of preparing acts of terrorism and was subsequently further arrested on suspicion of attempted murder. He was not known to security services before Tuesday.
Coventry University near Birmingham confirmed that Khater was a student between September 2017 and May 2018.
“Salih Khater studied accountancy at Coventry University between September 2017 and May 2018. As of May 2018 he is no longer enrolled at the university,” said a press statement from the university.
What did his local community have to say?
Nassar Mahmood from the Birmingham Central Mosque spoke to members of the local Sudanese community who told him Khater had gone to Sudan's consulate in London for visa reasons.
Mahmood said he had heard that Khater was not a worshiper at the mosque and had shown no signs of radicalisation.
At what stage is the police investigation?
Video footage showed the car veering across the road and into a security lane leading to parliament before crashing into a barrier. No one else was in the car at the time of the crash and no weapons were found in the vehicle.
Three people were injured when a silver Ford Fiesta drove into cyclists and pedestrians Tuesday morning.
The car had been driven from Birmingham the night before and arrived in London the following morning.
It reportedly drove around the Tottenham Court Road area for nearly five hours before driving around Westminster for another 90 minutes before the crash.
Police released pictures of the Ford Fiesta and asked people to send them any information concerning its movements before the incident.
On Wednesday, authorities obtained a warrant to detain Khater for longer before deciding whether to charge him.
No other arrests were made, said police.
The car has now been removed and the security lane re-opened.
Britain's counter-terrorism police chief said that given the iconic location and method used, the incident appeared to be a "deliberate act" and that it was therefore being treated as a terrorist incident.
In a statement, police said the priority of the investigation "continues to be to understand the motivation behind the incident".
The statement added officers were still searching one address in Birmingham but had completed investigations at the two other properties in Birmingham and Nottingham.