1. The attack unfolded around 2:40 pm (London Time) when the attacker drove a large vehicle at speed, mowing down pedestrians on Westminster Bridge, leading to Parliament
One woman was thrown from the bridge into the river Thames. She was later pulled alive from the water. However, another woman fell onto a hard surface below the bridge.
2. He killed two people and injured at least 20 other people, before crashing the vehicle into railings
Mark Rowley, the head of the counter-terrorism at the Met, said at least 20 people, including three officers, were hurt in the attack on the bridge.
"This is a day we have planned for but hoped would never happen, sadly it’s now a reality,” he was quoted as saying by The Guardian. “The attack started when a car was driven over Westminster Bridge hitting and injuring a number of members of the public, also including three police officers on their way back from a commendation ceremony."
3. After the car crashed, the man got out and approached Parliament, where he stabbed an armed officer to death
4. The attacker, in turn, was shot dead by the police
A total of four people were killed, including the police officer protecting parliament and one man believed to be the attacker, who was shot by a police officer.
5. Police say they are treating it as a terrorist attack and a "full counterterrorism investigation was underway"
6. Prime Minister Theresa May, who was in Commons, was taken from the scene in a silver Jaguar as gunfire erupted
See the photos, some of them graphic, from the attack: