At least three people have died and 20 more injured after a car mowed through crowds outside the UK parliament.
After the vehicle came to a halt, the man rushed out and stabbed a policeman at the entrance of the parliament building before being shot dead by other members of the security team.
The incident began at around 2.30pm GMT.
Police confirm four people killed including one police officer.
At least 20 people injured, some critically.
One attacker also shot dead by police after stabbing one police officer.
The attacker was involved a car that hit pedestrians on Westminster bridge, before crashing near parliament itself.
MPs and government staff were locked inside parliament at Westminster, though they were all later released, several hours after the attack.
PM Theresa May addresses the UK, describes the attacker as ‘sick and depraved. She pays tribute to the security services and condoled with families of those caught up in the attack
PM May stressed that the British people "will all move forward together” and parliament will sit as normal on Thursday.
Queen's visit to police HQ postponed. She was scheduled to visit the London police’s new headquarters on Thursday, but in the wake of today's attack, this visit has been postponed to a later date.