A number of amateur boxers were caught up in the Westminster terror attack on Wednesday after visiting the House of Commons ahead of the World Series of Boxing clash between the British Lionhearts and the Italia Thunder teams.

Four people have been confirmed to have died following Wednesday’s terror attack, during which a man drove through pedestrians on Westminster Bridge before crashing into the gates of the House of Commons. The man, who is among the fatalities, then stabbed a policeman before being shot by armed officers.

The Metropolitan Police confirmed on Thursday morning that the attacker, policeman and two members of the public have died, with 29 people still in hospital, seven of which are in a critical condition.

Seven arrests have been made after six police raids across London and Birmingham overnight, though the identity of the Westminster attacker is yet to be identified.

A number of reporters at the scene on Wednesday reported a large number of people in gym wear, with the Press Association’s Laura Harding noting the lobby of the Commons being “dominated by boxers in tracksuits”.

The Italia Thunder team were visiting the House of Commons when the attack unfolded, along with members of the Hammersmith Boxing Academy.

In pictures: Westminster attack Show all 9 1 /9 In pictures: Westminster attack In pictures: Westminster attack An air ambulance lands after gunfire sounds were heard close to the Palace of Westminster in London PA wire In pictures: Westminster attack MPs wait until the situation is under control in Westminster. 'The alleged assailant was shot by armed police,' David Lidington, leader of the House of Commons, told the house. BBC News In pictures: Westminster attack Crowds gather in Westminster after shooting incident, which police are treating as terror attack BBC News In pictures: Westminster attack Police were also called to an incident on Westminster Bridge nearby AP In pictures: Westminster attack Early reports indicate the car, which mounted the pavement on Westminster Bridge and mowed into around a dozen people, was the same vehicle which then rammed into the railings of the Palace of Westminster, just around the corner Reuters In pictures: Westminster attack Security sources described the suspected assailant as a middle-aged Asian man, who is understood to have left the car before attacking a police officer with a seven-to-eight inch knife PA wire In pictures: Westminster attack Police have asked people to avoid the immediate area to allow emergency services to deal with the ongoing incident AP In pictures: Westminster attack One woman has died and a number of others, including the police officer, have been hurt, according to a junior doctor at St Thomas' Hospital Reuters In pictures: Westminster attack At least three gun shots were heard by those inside Westminster, and proceedings in the House of Commons have been suspended AP

They took to Twitter to confirm they were safe from the attack, though British boxer Frazer Clarke was clearly shaken by the events that had unfolded.

“I can never unsee what I've just seen infront of my eyes at the House of Parliament in London ... God be with the police officer,” Clarke wrote on Twitter. “Currently inside the lobby at the Houses of Parliament terrible scenes ... God be with that police officer!! get me out of here ASAP.”

The Italia Thunder account added in Italian: “Not a good start [to] the adventure in London. Although at the time of the incident some of the #ItaliaThunder boxers were not far away, we want to reassure you that all are well.”