Westminster Bridge and the area just around parliament remained cordoned off on Thursday morning (23 March) after a knife-wielding man went on a deadly rampage in the heart of Britain's seat of power on Wednesday (22 March). The man, who was born in Britain and was known to intelligence services, ploughed a car into pedestrians on London's Westminster Bridge before stabbing a police officer to death inside the gates of Parliament. Isis has said that it was behind the attack, according to a statement released by the militant group.

Westminster attack: the day after
A bunch of roses is seen on the ground outside at the Metropolitan Police headquarters at New Scotland Yard, LondonJustin Tallis/AFP

Four people have been confirmed dead so far, following the attack, including the assailant, and 40 others were injured in what Prime Minister Theresa May condemned as a "sick and depraved terrorist attack." 29 people remain in hospital, seven of whom are in a critical condition. A doctor who treated the wounded on Westminster bridge told the Associated Press that some had "catastrophic" injuries.

The casualties include 12 Britons, three French children, two Romanians, four South Koreans, one German, a Pole, one Chinese, an American and two Greeks.

Forensic investigators could be seen examining the scene where the attacker was shot, while members of the public left floral tributes to police officer Keith Palmer, who was stabbed to while on duty.

Westminster attack the day after
A man lays flowers outside New Scotland Yard, LondonJack Taylor/Getty Images
Westminster attack the day after
A floral tribute left by a member of the public sits beside a photo of PC Keith Palmer, the policeman who was stabbed to death as he guarded the Palace of WestminsterJack Taylor/Getty Images
Westminster attack the day after
A floral tribute to the victims of yesterday's terror attack is left at the security cordon near Westminster Abbey, LondonDaniel Leal-Olivas/AFP
Westminster attack the day after
A message is left with flowers near the scene of yesterday's attack in LondonCarl Court/Getty Images
Westminster attack the day after
A woman pays her respects facing a floral tribute close to the Houses of Parliament, LondonJustin Tallis/AFP
Westminster attack the day after
Police officers in forensics suits search the grass on Parliament Square gardens outside the Houses of ParliamentJustin Tallis/AFP

Police have said they were treating the attack as terrorism and arrested eight people at six locations in London and Birmingham in the investigation into the lone-wolf attack, which Theresa May said was inspired by a 'warped Islamist ideology'. The threat level for international terrorism in the UK was already listed at severe, meaning an attack was "highly likely."

MPs gathered in Whitehall at 9:30am for a minute's silence which was held at 9:33am. Mayor of London, Saqiq Khan said that City Hall has invited Londoners to come together for a candlelit vigil that will held at Trafalgar Square from 6pm on 23 March.

Westminster attack the day after
A police forensics tent sits on Westminster BridgeJack Taylor/Getty Images
Westminster attack the day after
A Union flag flies at half mast from the Houses of ParliamentDaniel Leal-Olivas/AFP
Westminster attack the day after
British police officers bow their heads as they stand near a police cordon directly outside New Scotland Yard, LondonJustin Tallis/AFP
Westminster attack the day after
An armed police officer patrols by a security cordon set up along Whitehall by the Houses of Parliament, London.Justin Tallis/AFP
Westminster attack
Police officers stand guard on Whitehall, London Jack Taylor/Getty Images
Westminster attack the day after
Police officers patrol during rush hour at Victoria station, LondonDaniel Leal-Olivas/AFP
Westminster attack the day after
Metropolitan Police Service Acting Commissioner Craig Mackey salutes at New Scotland Yard during a minute silence to commemorate the victims of the terror attack at the parliament and on Westminster bridgeJustin Tallis/AFP