UK police have confirmed that four people have died as a result of Wednesday’s attack and 40 people have been injured.

FOLLOW RT’s LIVE UPDATES on Westminster terrorist attack

“We think we know who the attacker is,” Acting Deputy Commissioner & national lead for Counter Terrorism Policing Mark Rowley said but stated that they were not willing to divulge the assailant’s name at this time, though they did admit that it “Islamic terrorism is our assumption.”

A/Dep Cmsr Rowley: "At this stage - but it may change - we believe approx 40 people were injured including three police officers." — Metropolitan Police (@metpoliceuk) March 22, 2017

Police have also named the officer who died as 48-year-old husband and father PC Keith Palmer, a 15-year veteran of the force.

A/Dep Cmsr Rowley: "One of those who died was a police officer from our Parliamenary & Diplomatic Protection Command who had 15 yrs service" — Metropolitan Police (@metpoliceuk) March 22, 2017

What we know

Five people are dead, including a police officer and the alleged attacker

Several others have "catastrophic" injuries after a car reportedly mounted the pavement on Westminster Bridge and "tried to mow people down"

A woman was treated after "falling" from bridge into the River Thames

A police officer is dead after being stabbed inside Parliament grounds

The alleged assailant is dead after being shot by armed police

At least 40 people have been injured

Police are treating the incident as terrorism

Police believe there was only one attacker

PM Theresa May is chairing a COBRA emergency meeting

Five people have died, including one woman, the alleged attacker and a police officer.

Many others obtained "catastrophic" injuries, St Thomas' Hospital junior doctor Colleen Anderson told reporters.

Our thoughts are with the family of PC Keith Palmer @metpoliceuk a husband, a father and a colleague. pic.twitter.com/oFiJea4dcu — Terrorism Police UK (@TerrorismPolice) March 22, 2017

“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," Anderson said.



Mark Rowley, assistant commissioner of the Metropolitan Police, said the police are "satisfied at this stage it looks like there was only one attacker."

BREAKING: This is the man @PA is reporting is the attacker https://t.co/Rglrp4c7eepic.twitter.com/JFMJEZDFPW — Guido Fawkes (@GuidoFawkes) March 22, 2017

Shaky video of commotion after Parliament shooting. pic.twitter.com/ofGZwcMgaA — Patrick Daly (@thepatrickdaly) March 22, 2017

Close up image of knife used by terrorist in #London attack. pic.twitter.com/Cllt5TwKv0 — Paul Joseph Watson (@PrisonPlanet) March 22, 2017

London Ambulance Service says it has treated at least 10 patients on Westminster Bridge.

An eyewitness has told Sky News he saw a body "face down" in the Thames. Witnesses said people either jumped or were knocked over the side of the bridge as the car mounted the pavement and struck a number of pedestrians.

A spokesman for the Port of London Authority, which looks after safety on the river, said a female member of the public had been recovered from the water near Westminster bridge after she "fell" or "jumped" in.

"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."

My statement on the incident near Parliament Square this afternoon. Please visit https://t.co/NzFxlDdZ9N for the latest information. pic.twitter.com/T4s43cGzub — Mayor of London (@MayorofLondon) March 22, 2017

Shocking videos and photographs show people lying on the bridge, bleeding heavily, with members of the public rushing to their aid.

See more pictures from the terrorist incident in Westminster

An eyewitness, Richard Tice, described what he saw to RT.

“I came out of Westminster Tube at about 2:45pm when police were locking down the tube, ushering people out away from Parliament. I was ushered onto Westminster Bridge, and then I looked across the bridge, onto the west pavement,” he recalled.

READ MORE: ‘Stay under cover!’: Police evacuation captured in dramatic footage after Westminster attack (VIDEO)

“For the whole length of the bridge, from south to north, there were people lying on the ground and I was then told that a car had driven from the south end all the way up the pavement to the north end of the bridge. I counted at least eight people clearly injured on the ground.”

Incident in #Westminster: We are treating this as a terrorist incident until we know otherwise — Metropolitan Police (@metpoliceuk) March 22, 2017

Another witness described seeing a middle-aged man carrying a knife running towards the Palace of Westminster.

Kamal Alam, a Syrian military analyst whose office isn’t far from where the attack took place, also spoke with RT.

“I thought it’s just some kind of school drill, but within a few seconds heard what sounded like gunshots and a lot of screaming, and all of a sudden there [were] dozens of armed policemen telling everyone to run away from Parliament Square and Westminster Tube Station,” he said.

READ MORE: ‘If you work in Parliament, expect to come under attack at some point’ – MP

Jayne Wilkinson told Sky News: "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."

Impossible to be sure from here, but judging by the lack of resuscitation efforts it doesn't look good for either police officer or attacker — Jason Groves (@JasonGroves1) March 22, 2017

Foreign office minister Tobias Ellwood looking like he's sporting fresh blood #Londonpic.twitter.com/pEX4Zlsjnr — Hugh Dickinson (@Hugh_Dickinson) March 22, 2017

According to Doug Weeks, terrorism expert at London Metropolitan University, the attack, while softened by the high security presence in the area, could have been far bloodier.

“Well certainly within the Parliament compound itself, that is by far one of the most secure areas within London. There are numerous police officers and other security personnel that work in that area as well as around that area, thus it’s not surprising that the police have a very rapid response to this incident,” Weeks told RT.

Ariel view of Parliament scenes of the apparent security breach and shooting incident pic.twitter.com/8kjhB2RMxy — Ed Fraser (@frasereC4) March 22, 2017

Following the attack, Number 10 said Prime Minister Theresa May was safe. The spokesman declined to say where May was when the attack took place.

It is understood, however, she was rushed to a car 40 yards from the gates outside parliament where the shots were fired minutes after the attack. She was ushered by at least eight armed undercover police, some with their firearms drawn.

The leader of the House of Commons David Lidington said the alleged assailant was shot by armed police "inside the parliament perimeter."

Terror attack outside U.K. Parliament. 2 men down on road. Man with knife/machete got into Parliament and stabbed policeman. He's been shot pic.twitter.com/aYNktTiF4d — James West (@westicles69) March 22, 2017

A car on Westminster Bridge has just mowed down at least 5 people. pic.twitter.com/tdCR9I0NgJ — Radosław Sikorski (@sikorskiradek) March 22, 2017

Parliament and the surrounding area were placed on lockdown. Staff inside parliament were told to stay inside their offices.

VIDEO: Moment UK Parliament suspended following reports of gunfire incident outside. https://t.co/cph7eYKPT7pic.twitter.com/5qI1frfiPF — RT UK (@RTUKnews) March 22, 2017

My thanks to the police and all who responded so bravely to the shocking attack in Westminster. Our thoughts are with everyone affected. pic.twitter.com/593IYZlewD — Jeremy Corbyn MP (@jeremycorbyn) March 22, 2017

The London Eye was stopped and temporarily held all its "guests" within the attraction.

An air ambulance landed in Parliament Square shortly after the incident.

London Ambulance Service deputy director of operations Pauline Cranmer said it has "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."

Air ambulance landing in Parliament square pic.twitter.com/qmAUpyuNkN — Alistair Bunkall (@AliBunkallSKY) March 22, 2017

The US State Department said it was closely following the "concerning situation" in the UK.

"The Department of Homeland Security stands in solidarity alongside our friends in the United Kingdom in condemning the terrible attack at Parliament today. With our partners in federal law enforcement, we are in close contact with our British counterparts to monitor the tragic events and to support the ongoing investigation," it said in a statement.

.@POTUS has been briefed on the situation in the U.K. Continuing to monitor and update — Sean Spicer (@PressSec) March 22, 2017

The Muslim Council of Britain has issued a statement on the attack, which has not yet been claimed by any group.

Muslim Council of Britain statement on attack in Westminster https://t.co/4isOfWxnQapic.twitter.com/ucFkySiTwI — MCB (@MuslimCouncil) March 22, 2017

It has been one year today since the terror attack in Brussels.

READ MORE: London terrorist attack comes on 1st anniversary of Brussels bombings