Reports say the man arrested on suspicion of terror offences after the Westminster car crash has been named as Salih Khater.
The 29-year-old British citizen, originally from Sudan, is being questioned in south London.
He has been further arrested on suspicion of attempted murder, Scotland Yard said on Wednesday.
Three people were injured after a car hit cyclists and pedestrians during Tuesday morning’s rush hour.
The silver Ford Fiesta then crashed into security barriers outside the Houses of Parliament.
A man and a woman were taken to hospital after the crash and later discharged, while another man was treated for minor injuries at the scene.
The suspect is not believed to have been known to MI5 or counter-terrorism police, but is understood to have been known to local police.
He did not co-operate with officers after his arrest, Scotland Yard said. The investigation team’s priority “continues to be to understand the motivation behind this incident”, a spokesman added.
Police have concluded searches of two properties in Birmingham and one in Nottingham, and are currently searching a third address in Birmingham.
Mr Khater is believed to have lived in a first-floor flat above a parade of shops in the Sparkbrook area of Birmingham until four months ago, when he moved to the city’s Highgate area.
Neighbours called him a quiet man who frequently visited an internet cafe and a nearby shisha lounge, both on Stratford Road.
Local resident Ahmed Abdi described him as a man who “never spoke to anybody”, and added: “I recognised his picture from the news and I was shocked.”
Mr Khater studied accountancy at Coventry University from September 2017 to May this year, a spokesman for the university said, and is no longer enrolled there.
Before that, he studied a diploma in science at South and City College in Birmingham from 2014 to 2017, and studied English as a second or foreign language at City College from 2010 to 2011.