A 29-year-old man arrested following the incident in Westminster yesterday, Tuesday 14 August, remains in custody at a south London police station.
The man, who is a UK national originally from Sudan, was arrested at the scene by armed officers.
He was arrested on suspicion of the commission, preparation and instigation of acts of terrorism, under section 41 of the Terrorism Act (TACT) 2000, and detained under TACT.
He was subsequently further arrested for attempted murder.
The investigation is being led by the Met’s Counter Terrorism Command, with support from the wider counter terrorism policing network.
Police officers have concluded their searches of two addresses in Birmingham and another in Nottingham. They continue to search a third address in Birmingham.
At 07:37hrs on 14 August, a silver Ford Fiesta collided with cyclists and pedestrians before crashing into barriers outside the Houses of Parliament.
A man and a woman were taken to hospital with non-life threatening injuries and have now both been discharged. Another man was also treated at the scene.
At the time of the arrest, there was nobody else in the vehicle, which has now been removed from the scene and searched. No weapons have been recovered at this stage.
Given that it appears to have been a deliberate act, the method used and the iconic location, it is being treated as a terrorist incident and the investigation is being led by officers from the Met’s Counter Terrorism Command.
We are satisfied that we know the identity of the arrested man. The priority of the investigation team continues to be to understand the motivation behind this incident.
Detectives have today released images of the Fiesta involved, as they appeal for public assistance to identify its movements in the hours leading up to the incident.
The privately-owned Fiesta, registration number FL10 CWZ, travelled from Birmingham to London late on Monday night (13 August), arriving in the London area just after midnight (14 August).
The vehicle was in the Tottenham Court Road area from approximately 01:25hrs until 05:55hrs. It was then driven around the Westminster and Whitehall area from approximately 06:00hrs and stayed in this area until the time of the incident.
Officers are appealing to anyone who may have seen the vehicle or the driver either in the Tottenham Court Road area in the early hours of the morning of Tuesday, 14 August, or in the Westminster area from 06:00hrs the same morning, to contact them on 0800 789 321.
Anyone with footage or images of the incident is also asked to send these to the investigation team via our website http://www.ukpoliceimageappeal.co.uk/
At this early stage, there is no intelligence of further danger to Londoners or the rest of the UK in connection with this incident.
All cordons in the Westminster area have now been lifted.
At this stage, there have been no other arrests in connection with this investigation.
In addition, Project Servator officers, who have specialist skills to recognise tell-tale signs that that someone may be in an area for terrorist or other criminal purposes have been deployed in Westminster. These officers are both in uniform and plain clothes and will confront anyone they suspect may be in an area for criminal purposes.