The BBC reported eyewitnesses saying how the silver car appeared to deliberately hit members of the public.

"The car had struck a barrier on a lane used for access to the parliament building with force," witness Jason Williams bold Reuters. "It's a very serious incident. There was smoke coming from the vehicle."

Images shot by a Euronews journalist showed police pointing their guns at a vehicle. Footage on social media showed a handcuffed man being led away by heavily armed police. Other footage showed a cyclist lying on the street.

Parliament is in summer recess and most lawmakers are not using the building and Prime Minister Theresa May is on holiday abroad.