Police name officer who died in Westminster terrorist attack which killed four people as PC Keith Palmer

It has now been confirmed four people have lost their lives in this afternoon's attack in Westminster.

That includes the alleged attacker and one serving police officer, PC Keith Palmer. PC Palmer was unarmed when he confronted his assailant.

Around 40 others have been injured in the Westminster terror attack, Scotland Yard's top anti-terror officer Mark Rowley has confirmed.

Prime Minister Theresa May has described the actions of the lone knifeman as 'sick and depraved'.

Speaking outside 10 Downing Street after chairing a meeting of the Government's Cobra emergencies committee, Mrs May paid tribute to the 'exceptional men and women' of the police force who responded to the attack.

She confirmed that a single attacker drove a car into pedestrians walking on Westminster Bridge, killing two of them, before running with a knife through the front gates of the Palace of Westminster, where he killed a police officer before being shot dead.

She vowed that 'the forces of evil' would never be allowed 'to drive us apart'.

The attacker mowed down several pedestrians as he drove a grey Hyundai i40 across Westminster Bridge before crashing it into railings then running through the gates of the Palace of Westminster and stabbing the officer.

Police believe the incident was caused by a lone attacker.

Speaking to reporters outside the central London hospital, junior doctor Colleen Anderson from St Thomas' Hospital said a female pedestrian had died.

She also said she treated a police officer in his 30s with a head injury who had been taken to King's College Hospital.

She said: 'I confirmed one fatality. A woman. She was under the wheel of a bus.

'She died, confirmed her death at the scene.'

Ms Anderson also said: 'There were people across the bridge. There were some with minor injuries, some catastrophic.

'Some had injuries they could walk away from or who have life-changing injuries.

'There were maybe a dozen (injured).'

What we know so far

:: Emergency services are called at 2.40pm to an incident in the area of Parliament Square. It emerges that an 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 a policeman before being shot dead by other officers.

:: MPs are told the chamber would 'remain in lockdown' until further notice and business is suspended.

:: At around 3.30pm Scotland Yard says the attack is being treated 'as a terrorist incident until we know otherwise'.

:: The first death is confirmed after 4pm when a junior doctor at St Thomas' Hospital says one woman has died and a number of others have been hurt - including some with 'catastrophic' injuries.

:: Before 4.50pm, Commander BJ Harrington of the Metropolitan Police says there are 'a number of casualties' in the attack 'including police officers'.

:: London Ambulance Service say before 5pm that at least 10 patients were treated on Westminster Bridge and a number of hospitals are on alert.

Emergency personnel close to the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Yui Mok/PA Wire (Image: Press Association)

:: Before 5.40pm, sources say a police officer stabbed at the Houses of Parliament has died.

:: At about 6pm, Scotland Yard's top anti-terror officer Mark Rowley confirms four people were killed, including the police officer who was stabbed and his attacker.

:: Before 6.45pm, a spokesman for 10 Downing Street says Prime Minister Theresa May will shortly chair a meeting of the Government's emergency Cobra committee to discuss the immediate response to the incident in which at least 20 other people were injured. She orders flags to be lowered to half mast over Downing Street as a mark of respect to the innocent people who lost their lives, and a spokesman says she is being kept updated about the investigation.

Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Yui Mok/PA Wire (Image: Press Association)

Pauline Cranmer, deputy director of operations for London Ambulance Service, 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 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.'

Mounted police in Trafalgar Square, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Jonathan Brady/PA Wire (Image: JONATHAN BRADY)

Commander BJ Harrington of the Metropolitan Police said there were 'a number of casualties' in the Westminster attack 'including police officers'.

Eyewitnesses said the attacker was shot by police as he approached a second officer clutching his knife.

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

A crashed car on Bridge Street by the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture:Kathy Casatelli/PA Wire

Armed police cleared the area around the incident and Parliament Square was closed to traffic.

A Downing Street source confirmed that Prime Minister Theresa May was 'OK'.

Mrs May was seen being ushered into a silver Jaguar car as what sounded like gunfire rang out at Parliament during the incident at around 2.45pm.

Emergency personnel close to the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Yui Mok/PA Wire (Image: Press Association)

The incident comes exactly a year after suicide bomb attacks on the Brussels airport and underground system, which killed 32 people.

More than 300 people were wounded in the attacks, which were claimed by the Islamic State (IS) group.

The suicide bombings were Belgium's worst terror attacks.

Emergency personnel close to the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Yui Mok/PA Wire (Image: Press Association)

A year on, Belgium is still on a high state of alert, with soldiers patrolling the streets.

As the sitting in the House of Commons was suspended this afternoon, 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.

Emergency personnel close to the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Yui Mok/PA Wire (Image: Press Association)

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

'There are also reports of further violent incidents in the vicinity of the Palace of Westminster but I hope colleagues on all sides will appreciate that it'd be wrong of me to go into further details until we have confirmation from the police and from the House security authorities about what is going on.'

A spokesman for the Port of London Authority, which looks after safety on the River Thames, said: 'A female member of the public was recovered from the water near Westminster Bridge. She is alive but undergoing urgent medical treatment on a nearby pier. We believe she fell from the bridge.'

A crashed car on Bridge Street by the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture :Kathy Casatelli/PA Wire

He said the river has been closed from Vauxhall to Embankment 'as part of the security response'

MORE: Our reporter in Houses of Parliament describes the scene George Freeman, Conservative MP for Mid-Norfolk tweeted: 'Just walking past Portcullis entrance to vote and heard shouting and then rushed away by the Police. Two shots fired apparently....'

North Norfolk MP Norman Lamb tweeted: 'My team are ok. Locked in an office in Portcullis House. I'm in New Scotland Yard - panic set in as MPs went to vote and shot heard.'

Emergency services at the scene outside the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Stefan Rousseau/PA Wire

Vicky Ford, Conservative MEP for the East of England tweeted: 'In Westminster in Parliament, My team and I are all OK. Lockdown. Thinking of those outside.'

Brandon Lewis, Conservative MP for Great Yarmouth tweeted: 'Thoughts with injured police officer & all those keeping our Parliament and people safe right now.'

Richard Bacon, Conservative MP for South Norfolk, said MPs remained in lockdown, but the mood in Parliament was calm. He said: 'There's been an announcement that at some point, we might be able to leave in groups of 20, but we're waiting to see.

Emergency services at the scene outside the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. PRESS ASSOCIATION Photo. Picture date: Wednesday March 22, 2017. See PA story POLICE Westminster. Photo credit should read: Stefan Rousseau/PA Wire

'The mood here is calm. People are looking at their telephones and watching the television to get information on what has happened.

'It's obviously very horrific, what has been going on. I am sure there will be an extremely thorough investigation and a review of security. I think that's pretty inevitable.'

Alex Mayer, Labour MEP for the East of England, said: 'The unfolding events in London are heart breaking. Only this morning we commemorated the one year anniversary of the Brussels bombings.

An Air Ambulance outside the Palace of Westminster, London, after sounds similar to gunfire have been heard close to the Palace of Westminster. A man with a knife has been seen within the confines of the Palace, eyewitnesses said. Picture Victoria Jones/PA Wire

'My thoughts are with everyone affected and the emergency services that we all rely on at times like this.

'We need to stay united. Terrorists will never destroy our way of life and democracy must always win.'

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

Police outside the Palace of Westminster. Photo: Victoria Jones/PA Wire

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.

Emergency services close to the Palace of Westminster, London, after sounds similar to gunfire have been heard close to the Palace of Westminster. A man with a knife has been seen within the confines of the Palace, eyewitnesses said. Photo: Yui Mok/PA Wire (Image: Press Association)

'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'.'

Emergency services close to the Palace of Westminster, London, after sounds similar to gunfire have been heard close to the Palace of Westminster. A man with a knife has been seen within the confines of the Palace, eyewitnesses said. Picture: Yui Mok/PA Wire

Lord Brian Paddick said there was a 'suspect package' outside Parliament which police have had to deal with before the building can be evacuated.

'There was a suspect package attached to a vehicle outside Parliament,' the retired police officer told the BBC.

'Armed officers searched the whole of the Parliament estate to make sure there were no suspects outstanding.'

Emergency personnel close to the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Photo: Yui Mok/PA Wire (Image: Press Association)

MORE: Eyewitness saw 'man approaching the police officer probably with a knife'After the incident, Radoslaw Sikorski posted a video to Twitter purporting to show people lying injured in the road on Westminster Bridge.

Mr Sikorski, a senior fellow at Harvard's Centre for European Studies, wrote: 'A car on Westminster Bridge has just mowed down at least 5 people.'

Press Association Political Editor Andrew Woodcock witnessed the scenes unfolding from his office window overlooking New Palace Yard.

'I heard shouts and screams from outside and looked out, and there was a group of maybe 40 or 50 people running round the corner from Bridge Street into Parliament Square,' said Mr Woodcock.

'They appeared to be running away from something. As the group arrived at the Carriage Gates, where policemen are posted at the security entrance, a man suddenly ran out of the crowd and into the yard. He seemed to be holding up a long kitchen knife.

'I heard what sounded like shots - I think about three of them - and then the next thing I knew there were two people lying on the ground and others running to help them. Armed police were quickly on the scene and I heard them shouting to people to get out of the Yard.'

Ambulances on Westminster Bridge, London after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Scott D'Arcy/PA Wire

MORE: Norwich MP describes moment he was told police officer stabbed, assailant shot and people mown down outside Houses of ParliamentPress Association reporter Laura Harding, who was in Westminster at the time of the incident, said: 'Everyone has been evacuated into Central Lobby, including a group of schoolchildren and kitchen staff - around 15 schoolchildren aged around 10 - with armed police coming through the lobby now.

'The children are really calm, the teachers are comforting them.

'Everyone is standing around on their phones.

A police river boat on the River Thames at the Houses of Parliament, after a policeman was stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Jonathan Brady/PA Wire

'There are also a bunch of young people from the Hammersmith Boxing Club in their tracksuits and the British Lionhearts boxing group.'

A woman at the scene was on the opposite side of the square when she heard shots ring out at about 2.45pm.

She said: 'We literally just heard shots and then saw people running, and we went to have a look.'

Emergency personnel close to the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Yui Mok/PA Wire (Image: Press Association)

The woman, 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.

Ambulances on Westminster Bridge, London after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Scott D'Arcy/PA Wire

'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.'

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.

The view along Victoria Embankment towards parliament, after a policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Jonathan Brady/PA Wire

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.'

Ambulances on Westminster Bridge, London after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Scott D'Arcy/PA Wire

The Prime Minister was seen getting into the back of a silver Jaguar before driving off - first apparently heading to Black Rod's entrance but then turning towards Carriage Gates, near to where the incident took place.

Mrs May's official spokesman said: 'The Prime Minister was brought back to Number 10 from Parliament. She is currently monitoring the situation.'

She will chair a meeting of the government's emergency Cobra committee later today, a Downing Street spokesman said later.

A police river boat on the River Thames at the Houses of Parliament, after a policeman was stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Jonathan Brady/PA Wire

In a statement Labour leader Jeremy Corbyn said: 'Reports suggest the ongoing incident in Westminster this afternoon is extremely serious.

'Our thoughts are with the victims of this horrific attack, (their) families and friends.

'The police and security staff have taken swift action to ensure the safety of the public, MPs and staff, and we are grateful to them.'

The view along Victoria Embankment towards parliament, after a policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Jonathan Brady/PA Wire (Image: JONATHAN BRADY)

Scotland Yard said in a statement: 'Police are asking people to avoid the following areas: Parliament Square; Whitehall; Westminster Bridge; Lambeth Bridge; Victoria Street up to the junction with Broadway and the Victoria Embankment up to Embankment tube.

'This is to allow the emergency services to deal with the ongoing incident.

'Officers - including firearms officers - remain on the scene and we are treating this as a terrorist incident until we know otherwise.

Emergency services at the scene outside the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Stefan Rousseau/PA Wire

'We thank the public for their assistance.'

The Met Police is appealing for anyone with photos or footage of the incidents to pass it to them.

'If you have photos or film of the incident in £Westminster please make sure you pass them to police http://www.ukpoliceimageappeal.co.uk' the force tweeted.

Armed police at the scene outside the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Stefan Rousseau/PA Wire

Buckingham Palace declined to comment about its security arrangements in light of the terrorist incident and referred all inquiries to the Met Police.

But with the Royal Standard flying above the palace - indicating the Queen was in residence - it was clear some precautions had been taken as the gates, patrolled by armed police, had been closed.

A joint statement from Commons Speaker John Bercow and Lord Fowler, the Lord Speaker, said: 'On behalf of Members of both Houses of Parliament, we wish to offer our thoughts to all those affected and their families.

Armed police at the scene outside the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Date: Wednesday March 22, 2017. Picture: Stefan Rousseau/PA Wire

'We would also like to express our gratitude to the police and all emergency services.'

The London Eye tourist attraction, just across the Thames from Parliament, said it was on lockdown following the attack.

A spokesman said: 'At present we are holding all of our guests within our attractions as per tried and tested security procedures.'

Police close to the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Yui Mok/PA Wire (Image: Press Association)

More to follow.

Conservative MP Tobias Ellwood (centre) stands amongst the emergency services at the scene outside the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Stefan Rousseau/PA Wire

People remain in pods on the London Eye after it was stopped, after a policeman was stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Jonathan Brady/PA Wire

A Police dog and handler close to the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Yui Mok/PA Wire (Image: Press Association)

A Police dog and handler close to the Palace of Westminster, London, after policeman has been stabbed and his apparent attacker shot by officers in a major security incident at the Houses of Parliament. Picture: Yui Mok/PA Wire (Image: Press Association)

The location of the terrorist attacks in London. Graphic: KAYLEIGH O'DELL (Image: Archant)