Police have searched two addresses after a 29-year-old man drove into pedestrians and cyclists near Britain's Houses of Parliament on Tuesday.

He's been named as Salih Khater - a British citizen of Sudanese origin.

His actions are being treated as terrorism, although an exact motive is unclear.

Police on Wednesday said that they are searching two addresses in central England.

But that no further arrests have been made.

Reports say the man who carried out the apparent attack was known to police, although not to intelligence agencies. 

London's Mayor Sadiq Khan urged people in the city to be cautious, as Prime Minister Theresa May called the incident 'shocking'.

Parliament was cordoned off, but as it's in summer recess few lawmakers were there at the time.

London's political district has witnessed similar scenes before.

In March last year, Khalid Masood killed four people when he drove through crowds on nearby Westminster Bridge.

He then stabbed a police officer to death in the parliament grounds before being shot dead.

The UK is on its second-highest threat-level of "severe".