London attack: Acting Met Police commissioner Craig Mackey a 'significant witness' to terror attack

Acting commissioner of the Metropolitan Police Craig Mackey is being treated as a "significant witness" to the London terror attack.

Commander BJ Harrington, from the Met Police, said the acting commissioner was at the scene when the incident started.

Unconfirmed reports say that two people have died and many other are injured after a suspected terrorist incident at Westminster.

Emergency services were called to the scene at around 2.40pm on Wednesday (March 22).

Eyewitnesses are saying that an assailant ran over pedestrians on Westminster Bridge and attacked police officers with a knife outside Westminster. The assailant was then shot by armed police officers.

Commander BJ Harrington released a statement at around 4.45pm on Wednesday afternoon.

He said: "We received a number of different reports - which included a person in the river, a car in collision with pedestrians and a man armed with a knife.

"Officers were already in the location as part of our routine policing operation. Immediately, additional officers were sent to the scene and that included firearms officers."

He added: "We know there are a number of casualties, including police officers, but at this stage we cannot confirm numbers or the nature of these injuries."

Commander Harrington said Mr Mackey is being treated as a "significant witness" as he was at the scene when the incident started.

"While he is not injured it would be inappropriate for him to be here to talk about the incident at this stage," he said.

"Ours and his thoughts are with all those involved and those responding to both incidents."

Commander Harrington advised people to avoid the following areas: Parliament Square; Whitehall; Westminster Bridge; Lambeth Bridge; Victoria Street up to the junction of Broadway; and the Victoria Embankment up to Embankment tube station.

He said: "Public safety is our top priority and we are reviewing out policing stance across London and throughout the course of this afternoon there will be additional police and officers deployed across the capital.

"I would like to ask the public to remain vigilant and let us know if they see anything suspicious that causes them concern if they do call 999 immediately."

The commander urged anyone with information, pictures or moving images to call 0800 789321 or visit the website here .