London terror attack: What we know so far about shooting at the Parliament in Westminster
The knife-wielding attacker was shot by police, shortly after about a dozen people were mowed down by a car on Westminster Bridge.
Prime Minister Theresa May was bundled into a car by plain-clothed police officers and taken to safety. It is known that Mrs May is safe.
The House of Commons has been suspended for the day, while MPs are being held inside the building.
An air ambulance later landed in Parliament Square as paramedics rushed to and several people are known to have been injured.
More to follow.