- Updates on Wednesday 22 March
Updates on BBC London Live covering the attacks at Westminster have now ended for the day but our UK colleagues will be bringing you the very latest news and information throughout the night.
What we know so far:
- A police officer has died after being stabbed outside the Houses of Parliament
- At least one other woman has died and several others are critically injured after a car hit people on Westminster Bridge
- The alleged assailant was shot by armed officer
- The Met say they are treating as a terrorist incident
- Copyright: BBC
Labour MP Mary Creagh arrived at the scene shortly after the incident.
She told the BBC: "When we were on our way to vote there were armed police officers standing at the escalator.
"As I got off the escalator I saw people running towards me. Penny Mordaunt [another MP] ran up and said 'shots have been fired, we need to get out now'.
"We had no choice but to go out of the revolving doors one at a time - I shouted to the security guard 'you've got to open the doors' and he then opened them.
"I found myself in Westminster Tube station, I thought the one thing we don't want is tourists wandering in with their children into this situation.
"I went into the control room and told the controller 'there's been what we think is a terror attack on the Palace of Westminster and I said 'you need to shut the station now'."
The Port of London Authority have said the River Thames has been closed between Vauxhall Bridge and Embankment.
A4 London eastbound severe disruption, between St James's Street and Trafalgar Square.
A4 London - A4 Pall Mall in Westminster closed eastbound between the St James's Street junction and the Trafalgar Square junction, because of a security alert.
To report traffic and travel incidents dial 0330 123 0184 at any time
The RNLI has confirmed the Tower lifeboat was requested to launch twice to help deal with the attack.
It was first launched at 14:25 in connection with the incident then again at 15:55.
The boat returned to the station at 17:10.
BBC Local Live
The head teacher of Holy Family Catholic Primary School in Small Heath, Birmingham, Peter Foley, has reiterated the pupils who had been visiting Parliament are safe.
The school Twitter account published a photo of the children there shortly before the terrorist incident on Westminster Bridge unfolded.
He said: “All the children on the school trip are safe and their parents have been informed of the situation. The deputy head teacher is with the children and is providing me with regular updates.”
Transport Correspondent, BBC London
I'm on Waterloo Bridge where not much traffic is moving because of the road closures in place.Copyright: BBC
No boats are moving on this part of the River Thames.Copyright: BBC
You can also see people on the London Eye but it is not moving.Copyright: BBC
Prominent police blogger, former Met borough commander and police negotiator tweets:
Former newspaper political editor tweets:
The Church of England has shared a prayer for Westminster on twitter.
Transport correspondentCopyright: AP
British Transport Police tell me they have extra officers out tonight across the whole British rail network, not just London, in order "to reassure" people.
No numbers have been given and they aren't clear if they will be armed or not.
To be clear, they say it's just to reassure people, not because of a specific threat. But you could see a bigger presence going home tonight.
A police officer stabbed in the attack at the Palace of Westminster earlier died at the scene, says the minister who gave mouth-to-mouth resuscitation .
Three French high school students are among those who have been hurt in the attack, French media are reporting.
They were part of a visiting group from a school in the town of Concarneau in Brittany.
The students were hit by the car that drove into pedestrians on Westminster Bridge. One of the students is in a critical condition, Ouest France newspaper reported . Another has serious injuries and there is no information on the condition of the third student, the newspaper said.
After the incident the students were evacuated onto a boat and taken back to the hostel they were staying at, Le Telegramme newspaper reported .
- Copyright: BBC
Full statement from Metropolitan Police Commander, BJ Harrington:
"Since 2.40 pm this afternoon the [Metropolitan Police Service] has responded to an incident in the area of Parliament Square.
The senior National co-ordination has declared this is a terrorist incident.
Although we remain open-minded to the motive, a full counter-terrorism investigation is already underway. 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."
- Copyright: Getty ImagesQuote Message: "I would absolutely stress to the public our number one priority, working with our partners, is to keep London safe. If people have information please dial the number - 0800 789321." from Commander BJ Harrington Metropolitan Police
Sightseers held on the London Eye for safety are now getting off, say the attractions bosses.
The Port of London Authority has confirmed that a seriously injured woman has been recovered from the Thames river.
Spoken Martin Garside said: "A female member of the public was recovered alive from the water, but with serious injuries.
"She has been brought ashore and is undergoing urgent medical treatment. The working assumption is that she fell or jumped from the bridge".
He added that the river is completely closed to vessels between Vauxhall Bridge and the Embankment