British police investigating a man who drove into pedestrians outside Parliament early on August 14 say they are searching three addresses in central England as part of their inquiries.
London's Metropolitan Police said counterterrorism officers were carrying out searches in two addresses in Birmingham and one in Nottingham.
The driver, a 29-year-old British national, was arrested on suspicion of preparing a terrorist act, police said in a statement.
Police said there had been no other arrests in connection with the investigation.
Witnesses said the driver appeared to intentionally drive the car at high speed toward the steel-and-concrete security barriers that surround the British Parliament.
They said he hit at least one pedestrian before turning onto the wrong side of the road and hitting several cyclists at a busy intersection outside Parliament, and then accelerating into the barrier.
A man and a woman were taken to hospital with non-life-threatening injuries and had already been discharged, while another man was treated at the scene, the police statement said.
Police said the crash appeared to be a "deliberate act" and that the arrested suspect was not cooperating with investigators. No weapons were recovered at the scene of the crash in London's Westminster area.
Police say the car, which was privately owned, had travelled from Birmingham to London late on August 13.
The vehicle was then driven around the Westminster and Whitehall area from approximately 6 a.m. until the crash at 7:37 a.m. on August 14.
"At this early stage, there is no intelligence of further danger to Londoners or the rest of the U.K. in connection with this incident," the statement said.
The security barriers were extended after the Westminster Bridge attack in March 2017, when Khalid Masood drove a car at a high speed into crowds on Westminster Bridge and then crashed into a gate outside Parliament, killing four people.
"My thoughts are with those injured in the incident in Westminster and my thanks to the emergency services for their immediate and courageous response," U.K. Prime Minister Theresa May tweeted.
"Another terrorist attack in London...These animals are crazy and must be dealt with through toughness and strength!" U.S. President Donald Trump tweeted on August 14.