An eyewitness to the Westminster "terrorist incident" has described the moment the knifeman struck.
Emergency services converged on Westminster at around 2.40pm on Wednesday afternoon (March 22).
Unconfirmed reports suggest an assailant ran over pedestrians and attacked police officers. There is a further claim that a person was shot.
The Metropolitan Police called it a "terrorist incident" and immediately appealed for witnesses.
One eyewitness spoke to the Chronicle Live following the ordeal.
He said: "I was just walking up to the station and there was a loud bang. Someone crashed a car and took some pedestrians out, and they were just laying there."
"The whole crowd just surged around the corner by the gates just opposite Big Ben.
"A guy came past my right shoulder with a big knife and just started plunging it into a policeman.
"I never seen anything like that, I just can't believe what I just saw."
Sky News reported that two people have died following the attack and other people have suffered serious injuries.
Anyone with information, pictures or video of the incident is asked to upload them to the Metropolitan Police website here .