Video from a rooftop camera shows the moment a car involved in an alleged terror incident crashed into barriers next to the Houses of Parliament on Tuesday morning.
Two vehicles, which appear to be police vans, can be seen behind the car shortly before the crash.
The silver Ford Fiesta is seen coming along the road next to Parliament Square before moving to turn right towards Westminster Abbey, the footage from BBC News shows.
As an ambulance passes the car on its right-hand side, the vehicle swerves left, crossing oncoming traffic and a pavement before entering a small road and crashing into a security barrier.
A police officer can be seen jumping another barrier that runs along the side of the road to get away.
Scotland Yard counter-terrorism head Neil Basu said the vehicles behind the suspect’s car were not following it and the ambulance seen in the clip was on its way to an unrelated incident.
A man in his 20s has been arrested on suspicion of terrorist offences.
No other suspects have been identified and there is “no intelligence at this time of further danger” to Londoners, Scotland Yard counter-terrorism head Neil Basu said.
He added the suspect was not known to intelligence services and was “not cooperating” with police.
The incident began just after 7.37am (BST). The London Ambulance Service confirmed they had treated three people at the scene for and two people had been taken to hospital.
One woman has “serious but not life-threatening” injuries and the other has since been discharged.
Scotland Yard said: “The driver of the car, a man in his late 20s, was arrested at the scene by armed officers. He has been taken to a south London police station where he remains in police custody.
“He was arrested on suspicion of terrorist offences.
“There was nobody else in the vehicle, which remains at the scene and is being searched. No weapons have been recovered at this stage.”