In pictures: Westminster car crash - BBC News
A man is arrested after a car crashes into security barriers outside the Houses of Parliament.
Armed police, ambulances and firefighters responded to an incident in central London, which happened shortly after 07:30 BST.

Officers were seen surrounding the silver car, which had crashed into a barrier outside Parliament, before a man was arrested.

Streets around Millbank and Parliament Square were cordoned off for several hours after the crash.

A vehicle swerved into cyclists and pedestrians, injuring three people.

Armed police were seen on Victoria Embankment in Westminster.

One women is being treated in hospital for serious but non life-threatening injuries.

Scotland Yard have said they are treating the crash as a terrorist incident.

Forensic officers examined the vehicle at the scene.