Around 20 people were hit when a 4×4 drove along the pavement on the crowded bridge, knocking down and seriously injuring pedestrians before crashing into a fence below Big Ben.
The killer, described by witnesses as ‘middle-aged and Asian’, then managed to break into the grounds of Parliament, where he fatally stabbed a police officer with two knives.
The policeman died at the scene. The attacker, who was shot at least twice by armed officers guarding the building, died after he was taken to hospital.
It is currently believed he was the only ‘lone wolf’ attacker and he three people have died, including the policeman. Around 20 pedestrians and three other police officers were injured.
Prime Minister Theresa May was bundled into her car by a plain-clothes police officer and driven quickly from the scene as the attack unfolded. She will chair a meeting of the Government’s emergency Cobra Committee tonight.
Scotland Yard said the attack, which comes a year to the day after the atrocities in Brussels, is being treated ‘as a terrorist incident’.