Local journalist Quentin Letts, whose London office overlooks the scene of an incident believed to be a terrorist attack, told the Ross Gazette that he had a bird's eye view of the incident.

He said he was in his office, completing his column for the Daily Mail, when he heard a terrible bang. This was the moment a car hit pedestrians on Westminster Bridge. He could see people panic-striken running from the scene and he saw a man, all in black, run through the vehicle entrance gates to the Houses of Parliament.

Mr Letts said that he saw the man run up to a policeman and he could see that the man had something in his hand and it looked as if he was either stabbing or striking a policeman. He then ran away and other police officers shouted at him to stop. The man didn't and they shot him. Mr Letts then had to watch as emergency services tended to the injured.

He said the police were fantastically brave. He is still in his office as it is in 'lock down'. He added: "Parliament Square is still closed, but it seems as if it returning to calm."

Metropolitan Police say they are treating an incident at the Houses of Parliament earlier this afternoon as a terrorist incident "until we know otherwise."

A police officer has been stabbed in the Houses of Parliament in central London which has been ’locked down’, although it is reported that Prime Minister Theresa May has left the building.

The alleged assailant was shot by armed police and witnesses have also reported seeing several people being "mowed down" by a vehicle on Westminster Bridge.

Local journalist Quentin Letts, whose office overlooks the scene, told the BBC of the moment police shot the man.

He said that the man had something in his hand which looked as if he was either stabbing or striking a policeman. He then ran away and was shot.