In pictures: Westminster car crash
Armed police, ambulances and firefighters responded to an incident in central London, which happened shortly after 07:30 BST.
BBCOfficers were seen surrounding the silver car, which had crashed into a barrier outside Parliament, before a man was arrested.
Reuters
PAStreets around Millbank and Parliament Square were cordoned off for several hours after the crash.
ShutterstockA vehicle swerved into cyclists and pedestrians, injuring three people.
Armed police were seen on Victoria Embankment in Westminster.
PA
PAOne 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.
PAForensic officers examined the vehicle at the scene.
PA.
