Westminster terror attack: Four dead and several injured as policeman killed by knifeman named

• Four people, including a police officer and the attacker, have died and more than 40 others wounded, some with catastrophic injuries

• One woman was killed on Westminster Bridge after a number of pedestrians were mowed down by a car

• It is believed a second person was also killed in the incident on the bridge

• Another woman ended up in the Thames and was treated for serious injuries after being pulled from the water

• A group of French schoolchildren were among those targeted on the bridge

• The attacker jumped out the car and fatally stabbed a police officer in the grounds of the Palace of Westminster

• The knifeman was shot dead moments later by another officer

• Police are treating the incident as a terrorist attack

• Prime Minister Theresa May chairs a meeting of the Government's emergency Cobra committee

• The Prime Minster called the events a "sick and depraved" attack

• Police officer fatally stabbed named as Keith Palmer, 48, who served for 15 years

The attacker, armed with two large knives, mowed down pedestrians with his car on Westminster Bridge, including schoolchildren, then rushed at the gates in front of the Houses of Parliament, stabbing the policeman before being shot dead by other officers.

Tonight Prime Minster Prime Minister Theresa May called today's attack in Westminster "sick and depraved".

She praised the bravery of the police officers "who keep us and our democratic institutions safe".

"Our thoughts and prayers go out to all who have been affected, to the victims themselves and to their families and friends, who waved their loved ones off but will not now be welcoming them home."

Scotland Yard's top anti-terror officer Mark Rowley said the two fatalities were on the bridge when the terrorist struck. Police today confirmed 29 people had been treated in hospital.

Mr Rowley told reporters outside New Scotland Yard, just yards from the scene of the attack: "This was a day we've planned for but hoped would never happen. Sadly it is now a reality."

Paramedics fought to save the officer's life and that of his attacker on the floor of the cobbled courtyard in front of Parliament, with Foreign Office minister Tobias Ellwood among those who rushed to help.

The police officer was wheeled away on a stretcher with his face covered.

Other armed officers, some in plain clothes and wearing balaclavas, swarmed around the yard just feet from where MPs had earlier attended Prime Minister's Questions.

The knifeman drove a grey Hyundai i40 across Westminster Bridge before crashing it into railings then running through the gates of the Palace of Westminster.

His attack left a trail of destruction as paramedics tended to victims on the bridge and at the gate.

One woman hit by the attacker's car before he reached Parliament was confirmed dead by a doctor at St Thomas' Hospital. She said others on the bridge suffered 'catastrophic injuries'.

Another woman who apparently fell into the Thames was rescued and given urgent medical treatment on a nearby pier.

London Ambulance Service said paramedics had treated at least 10 patients on Westminster Bridge.

A party of French schoolchildren were among those targeted on the bridge, with three injured.

Downing Street said Prime Minister Theresa May, who was ushered away from Parliament after the attack, was chairing a meeting of the Government's emergency Cobra committee.

Mrs May was seen being ushered into a silver Jaguar in the grounds of the palace as what sounded like gunfire rang out at around 2.45pm.

• MORE: 'I'm hiding under a table' - Midland MPs describe moment Parliament 'terror attack' unfolded

• MORE: How hero MP fought to save fatally injured police officer

• MORE: French schoolchildren among those injured on Westminster Bridge

Eyewitness Rick Longley described the attack.

"We were just walking up to the station and there was a loud bang and a guy, someone, crashed a car and took some pedestrians out.

"They were just laying there and then the whole crowd just surged around the corner by the gates just opposite Big Ben.

"A guy came past my right shoulder with a big knife and just started plunging it into the policeman.

"I have never seen anything like that. I just can't believe what I just saw."

A counter-terrorism investigation is already under way, police said.

Around three shots rang out as the attacker ran through the gates into the front yard of the parliamentary compound.

Two people - thought to be the knifeman and the officer - were then seen being treated on the ground in New Palace Yard amid shouts and screams.

An air ambulance landed in Parliament Square and a regular ambulance came in through the front gates as medics rushed to help the injured people.

Armed police cleared the area around the incident and Parliament Square was closed to traffic while Parliament went into lockdown.

Lichfield MP Michael Fabricant was in Parliament when the incident unfolded.

He said: "I was walking briskly to a vote when crowds of MPs rushed towards me saying that shots have been fired and shouts of 'get back'.

As the sitting in the House of Commons was suspended, Commons Leader David Lidington told MPs: "What I am able to say to the House is there has been a serious incident within the estate.

"It seems that a police officer has been stabbed, that the alleged assailant was shot by armed police.

"An air ambulance is currently attending the scene to remove the casualties."

Witnesses described seeing a middle-aged man carrying a knife and running.

Jayne Wilkinson said: "We were taking photos of Big Ben and we saw all the people running towards us, and then there was an Asian guy in about his 40s carrying a knife about seven or eight inches long.

"And then there were three shots fired, and then we crossed the road and looked over. The man was on the floor with blood.

"He had a lightweight jacket on, dark trousers and a shirt.

"He was running through those gates, towards Parliament, and the police were chasing him."

Her partner David Turner added: "There was a stampede of people running out.

"You saw the people and you thought 'what the hell is going on'."

A witness, who did not want to be named, saw Mrs May and her undercover police detail near the area of Parliament where ministerial cars are parked.

He said there were undercover officers in a 4x4 vehicle in the car park.

"We just heard gunshots inside Parliament," he said.

"It looked like they are taking her away."

Another witness, from South Africa and living in Ireland, said she and two friends went towards the palace gates and saw a man lying on the floor inside.

She said: "I saw a body, they were working on the floor. They were just inside the gates.

"He had one gunshot wound to the right side of his chest. I don't know if he was dead or alive, but people were working on him.

"I saw that needed medical attention and I asked if I could help because I am a doctor, but they said they were fine.

"Then the police moved us back."