London was hit by a terrorist attack on Wednesday and Prime Minister Theresa pledged later that evening that the capital would carry on “as normal” despite the “sick and depraved” attacks.

So far, at least four people have died and at least 40 were injured after a car drove into dozens of people on crowded Westminster Bridge and an attacker tried to break into Parliament with a knife.

The attacker stabbed a police officer, who has now died, before being fatally shot by police.

The Metropolitan Police are currently treating the incidents as terrorist attacks. It occurred on the anniversary of the Brussels airport terror attack.

Police raided six addresses, including a flat in Birmingham, and arrested seven people in connection to the London attack.

Here is how the attack unfolded.

WARNING: GRAPHIC IMAGES FOLLOW.


The incident began on Westminster Bridge on Tuesday at 2.40 pm G.M.T., when a car ran into several civilians.

Foto: source Toby Melville / Reuters

The car injured at least a dozen people on Westminster Bridge, including three French school children on a trip.

Foto: source Reuters / Toby Melville

Victims of the car attack were not yet been named. They were taken to the nearby St. Thomas' Hospital. One victim died there.

Foto: source Toby Melville / Reuters

One civilian (not pictured) either jumped into the Thames in order to escape from the attack or was thrown by the oncoming car. She was recovered from the river alive.

Foto: source Toby Melville / Reuters

Ordinary people immediately went to help the injured.

Foto: A woman assists an injured person after an incident on Westminster Bridge in London, March 22, 2017. source Reuters / Toby Melville

Radosław Sikorski, a Polish politician, captured the scene on Westminster Bridge moments after the attack, reporting that he saw at least five people injured.

Foto:

A car on Westminster Bridgehas just mowed down at least 5 people. pic.twitter.com/tdCR9I0NgJ

pic.twitter.com/tdCR9I0NgJMarch22, 2017


Shortly afterwards, a car crashed into railings outside the Houses of Parliament. It was reportedly the same vehicle involved in the bridge attack. Twitter user Luke Steele uploaded the image below:

Foto: source Luke Steele / Twitter


Moments after the car crashed, Metropolitan police shot an unidentified person in Parliament's New Palace Yard. The man had entered the grounds of Parliament and stabbed a police officer with a knife.

Foto: source Google Maps / Business Insider

Journalist Quentin Letts, who witnessed the incident, said: "I saw a fairly thick-set man wearing black clothes running through the open gates, the security gates where people drive their cars."

Letts added: "He started beating a policeman who had fallen over on the ground. The policeman managed to shake him off and the attacker then ran towards the entrance of the House of Commons, which is used by our members of Parliament and he got about 15 yards before the authorities responded."


Emergency services who arrived at the scene reported "catastrophic injuries." A statement from the 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."

Foto: source Toby Melville / Reuters

The area around Westminster Bridge was cordoned off by armed police immediately.

Foto: source Toby Melville / Reuters

A witness close to Westminster Bridge told Business Insider that there were "lots of sirens" and "people running" at the scene.

Foto: source Business Insider/Donald Sinclair

The area surrounding the Palace of Westminster was also cordoned off.

Foto: Police tapes off Parliament Square after reports of loud bangs, in London, Britain, March 22, 2017. source REUTERS/Stefan Wermuth

An air ambulance landed on Parliament Square carrying paramedics.

Foto:

VIDEO London HelicopterEmergency Medical Services landing near parliament in Westminsterafter firearms incident (footage: Gary Kittle) pic.twitter.com/XNuZTsg2vW

pic.twitter.com/XNuZTsg2vWMarch22, 2017


Paramedics tried to revive the injured in New Palace Yard, Westminster.

Foto:


Conservative MP Tobias Ellwood (centre) — a former soldier — helped emergency services attend to the injured police officer.

Foto: source Stefan Rousseau/PA Wire/PA Images

According to the Telegraph, Ellwood attempted to give the officer mouth-to-mouth resuscitation and stemmed the blood flow by applying pressure to the wounds. The BBC reports that the officer in question has now died.

Foto: source Stefan Rousseau/PA Wire/PA Images

Armed police swarmed the area, including specialist counter-terrorism officers like the man pictured running here.

Foto: source Stefan Wermuth / Reuters

The police set up a guard next to the statue of Winston Churchill.

Foto: source Stefan Wermuth / Reuters

Facebook quickly activated its "Safety Check" in London, which lets people tell their loved ones they are OK.

Foto: source BI/Facebook

This is the first photo of the suspected attacker being carried away from New Palace Yard.

Foto: source PA

Many peers from the House of Lords — along with parliamentary staff and a handful of MPs — were evacuated to nearby Westminster Abbey. Pictured, a Metropolitan Police superintendent addresses the crowd from the pulpit at the Abbey.

Foto: source Sam Lister/PA Wire/PA Images

The bulk of MPs were evacuated to Westminster Hall, where they remained as of 6.30 pm G.M.T.

Foto:


As of 6.30 p.m. GMT on Wednesday, police were yet to confirm that the incident was officially over.

Foto: source REUTERS/Stefan Wermuth

Commander BJ Harrington of the Metropolitan Police made a statement on the incident outside of New Scotland Yard. He confirmed that the matter is being treated as a terrorist incident.

Foto: source Jack Taylor / Stringer

Prime Minister Theresa May then went to chair a 45 minute meeting of the emergency COBR committee to discuss the government's immediate response to the incident.

Foto: source Olivier Matthys AP/Press Association Images

London Mayor Sadiq Khan released a video on his Facebook page saying "Londoners will never be cowed by terrorism."

Foto: source Sky News


Then May addressed the nation around 9 p.m. GMT and condemned the "sick and depraved" attacks in London. She pledged normality for Britons despite Wednesday's events.

Foto: source Sky News

Watch in full: PM @theresa_may pays tribute tothe "exceptional men and women" of the emergency servicesafter terror attack at #Westminsterpic.twitter.com/d4dIAcf9K6

@theresa_may#Westminsterpic.twitter.com/d4dIAcf9K6March 22,2017


At around 10.30 p.m. GMT, Scotland Yard confirmed that 4 people, including the suspect, had died and 40 others were injured. The police would not name the suspect.

Foto:

Police confirm five dead and40 injured in #Westminsterterror attack. Several with serious injuries, including threepolice officers pic.twitter.com/2AyXtw2UBg

#Westminsterpic.twitter.com/2AyXtw2UBgMarch 22,2017


However, the police confirmed that PC Keith Palmer, a 48-year-old husband and father, was killed in Westminster attack. He was in the police force for 15 years.

Foto: source Scotland Yard

Meanwhile, around 11 p.m. GMT, France demonstrated its support and solidarity with Britain — after experiencing a series of horrific terrorist attacks previously — by switching off the lights on the Eiffel Tower. Several French school children are believed to be injured in the attacks in London.

Foto: source Sky News

In the early hours of Thursday morning, police raided six addresses and made seven arrests in connection to the London attacks.

Foto:

Arrests made in police raid inBirmingham which is linked to #Westminsterterror attack, Sky sources say @skymarkwhite pic.twitter.com/Sxh5odAkTA

#Westminster@skymarkwhitepic.twitter.com/Sxh5odAkTAMarch 23,2017


However, the Metropolitan Police still refused to confirm the identity and nationality of the terrorist suspect.

Foto:

Met Police won't confirmidentity of #London attacker,including whether he was a British national. Victims are of mixednationalities. pic.twitter.com/z0GDlUTM9v

#Londonpic.twitter.com/z0GDlUTM9vMarch 23,2017


Then at 10.30 a.m. GMT, Prime Minister Theresa May told MPs that the country is "not afraid" as she delivered her first speech to the House of Commons since the attack.

Foto:

"We are not afraid":Theresa May says in the Commons, making statement on the #London terrorattack #Westminsterpic.twitter.com/r2DGNsXDx7

#London#Westminsterpic.twitter.com/r2DGNsXDx7March 23,2017


Around midday, ISIS (also known as the Islamic State and Daesh) claimed responsibility for the attack in London via the jihadist propaganda news site Amaq.

Foto:


The first civilian victim that has been identified is Aysha Frade, a 43-year-old year mother of two (L). An American tourist from Utah in the US, Kurt Cochran, was the second civilian believed to have been killed in the attack.

Foto: source Sky News/Facebook