Here is an extract from the statement from the Metropolitan police commander, BJ Harrington.
Although we remain open-minded to the motive, a full counter-terrorism investigation is already under way. This is led by the Met counter-terrorism command.
At this stage I will confirm what we know has happened but I will not speculate. 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 that location as part of routine policing but immediately additional officers were sent to the scene and that included firearms officers. We are working closely with the London ambulance service and the London fire brigade ...
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 ...
The acting commissioner, Craig Mackey, is being treated as a significant witness as he was at the scene when the incident started. Whilst he is not injured, it would be inappropriate for him to be here to talk about this incident at this stage.
Our thoughts and his thoughts are with all those involved and responding to that incident this evening. I would stress that if anyone has information about today’s incident they are urged to call 0800789321 and I want to stress that if the public have any information or see anything suspicious to dial 999 immediately.
The London ambulance service deputy director of operations, Pauline Cranmer, has confirmed that they have treated at least 10 patients on Westminster Bridge.
He said:
We can confirm we have treated at least 10 patients on Westminster Bridge and have put a number of hospitals on alert as we continue to respond to this incident.
We were called at 2.40pm today, with the first ambulance crew arriving within six minutes.
We have sent a number of resources to the scene including ambulance crews, London’s air ambulance and our Hazardous Area Response Team.
We are working closely with other members of the emergency services at the scene, with our priority being to ensure patients receive the medical help they need as quickly as possible.
We have declared a major incident and our priority is to assess patients and ensure that they are treated and taken to hospital as soon as possible.
As we are very busy dealing with this incident, we would ask the public to only call us in a genuine emergency.
Commander BJ Harrington said there were a number of casualties but would not confirm any fatalities or the nature of injuries.
“We know there are a number of casualties including police officers but at this stage we can not confirm numbers or the nature of these injuries,” he said.
Craig Mackay, the acting Met commissioner, is being treated as a “significant witness” as he was at the scene when the attack started.
At 4.40pm some MPs and visitors to parliament were led out through Westminster Hall, the oldest part of the Palace of Westminster, walking across the corner of New Palace Yard where the incident occurred.
There are still around 20 police cars, at least six ambulances and five fire engines on Parliament Square, next to the New Palace Yard entrance.
Commander BJ Harrington from the Metropolitan police is speaking to reporters now.
Firearms officers were sent to the scene, he says. He appeals to the public to avoid areas around Westminster. This is to allow emergency services to deal with the “ongoing incident”.
He says there are a number of injuries, including police.
He says extra police officers are being deployed across the capital. The acting commissioner is a significant witness, because he was at the scene, he says.
He asks anyone with information about this to call the police.
World leaders have begun to react with shock to the incident in Westminster in which at least one person has died.
The US president, Donald Trump, described the incident as “big news” after he was updated on the situation. Trump told reporters: “I was just getting an update on London … some big news having to do with London just happened,” according NBC.
The US State Department said it was ready to assist the UK authorities in any way. State Department spokesman Mark Toner said: “We are following the concerning situation outside the UK parliament. Our hearts go out to those affected. We stand ready to assist in any way the UK authorities would find helpful. The safety and security of US citizens overseas is one of our priorities. Our embassy in London is monitoring the situation closely.”
The Dutch prime minister, Mark Rutte, said: “Horrible images from London. The very heart of the city has been struck. Our thoughts are with the British people.”
Gibraltar’s chief minister, Fabian Picardo, said: “Shocked at attack on London. Yesterday I spent the day at Westminster. Luckily not today. London’s Parliament is the mother of democracy!”
