A man has been arrested after a car crashed into security barriers outside Britain's Houses of Parliament in Westminster, injuring a number of pedestrians.

Dozens of emergency vehicles swarmed around Parliament Square with members of the public ordered to stay clear of the area.

Streets around Parliament Square, Millbank and Victoria Tower Gardens have been cordoned off as dozens of armed police swooped on the scene.

Armed officers surrounded the car before leading a man away in handcuffs.

There is no indication at this stage whether it's a terror incident.