Bus driver Mustafa Salih, 62, was travelling from Borough High Street towards London Bridge where he saw emergency vehicles and the police cordon.

He told BBC London: “A police officer came up to me and said turn off your engine, get off and run.

"I looked up and I could see a crowd of people coming towards me.

"One woman was crying. I ran back down to Borough High Street. It was all very scary as we did not know what was happening.”

Mr Basu did not take any questions from the press after delivering his statement.

The prime minister has requested a personal briefing, the officer says, adding he will be heading to Downing Street immediately.

Met Police assistant commissioner Neil Basu says officers from the Met's Counter Terrorism command are now leading the investigation.

"We retain an open mind as to any motive," he adds. "It would be inappropriate to speculate further at this time."

"Due to reports that the suspect may have had an explosive device, specialist officers also attended the scene and wide cordons are in place ensure there remains no further danger to the public."

Police have confirmed they are treating the stabbings, which ended with a man being shot by police, as a terrorist incident.

The UK's terrorism threat level was downgraded on November 4 from "severe" to "substantial", meaning that attacks were thought to be "likely" rather than "highly likely".

At the time, Home Secretary Priti Patel said: "Substantial continues to indicate a high level of threat, and an attack might well occur without further warning.

"As ever, the public should remain vigilant and report any concerns they may have to the police."

The terror threat level is reviewed every six months by the Joint Terrorism Analysis Centre, which makes recommendations independent of government.

Assistant commissioner Neil Basu adds that a "wide cordon remains in place" following the incident.

He says: "Officers continue to carry out extensive searches in the area to ensure there is no further threat to the public.

"Extensive cordons will remain in place for considerable time."

He adds that the force "will be enhancing police patrols both in the city and across London".

Assistant commissioner Neil Basu adds: "A number of other people received injuries.

"As soon as we can provide updates on their condition we will."

Met Police assistant commissioner Neil Basu tells reporters: "I can confirm at approximately 14:00 GMT today police were called to a stabbing at a premises near to London Bridge.

"A male suspect was shot by specialist armed officers from City of London Police and I can confirm that this suspect died at the scene."

Assistant commissioner Neil Basu adds: "I can confirm at this time we believe a device that was strapped to the body of the suspect is a hoax explosive device."

The Met Police press conference has begun.

The force has confirmed it is being treated as a terrorist incident.

During a campaign visit to Cardiff, Liberal Democrat leader Jo Swinson expressed concern over the incident at London Bridge.

Ms Swinson said: "Clearly, we don't know the exact details of what has happened, and my thoughts are with everybody who has been caught up in that incident in whatever way.

"Including, of course, the brave police who are dealing with it with professionalism and in the way in which they do become the first responders in these difficult times."

We're expecting an update from the Metropolitan Police shortly.

A BBC producer at the news conference says it's running a few minutes late.

A video filmed from a bus on London Bridge appears to show a suspect being shot as he lay on the ground.

Another man, wearing a suit jacket and coat, could be seen running away - after apparently having retrieved a large knife from the scene.

Image source, Twitter

Tom Symonds
Home Affairs Correspondent

I believe this is something that took some minutes to unfold.

The reason I'm thinking that is because there were two, possibly three, armed officers on the scene.

Unless there was a lucky break for the police and they just happened to be nearby, those officers will have had to have come in.

So it's possible that whatever was going on was going on for some time, and that passersby saw what was happening and got involved.

It looks like they got on top of this man and held him down.

A witness who works in a stall in Borough Market, on the south side of London Bridge says it looked like a minor incident at first.

But Laurence Verfaillie tells the PA news agency it brought back memories of the terror attack on the bridge and market in 2017.

"I thought it was a car crash, it looked like it was pretty minor," he says.

"Suddenly a trader told me the ice cream seller on the bridge has run away yelling there has been an incident.

"Another trader said police were looking for someone.

"Suddenly people were taking refuge in our shop before we got told to leave.

"We still think about what happened last time."