He threatened to detonate what turned out to be a fake suicide vest and started attacking people with two knives taped to his wrists, killing two of the conference participants by stabbing them in the chest.

Several people fought back, some attacking Khan with a fire extinguisher, a pike and a narwhal tusk as he fled the building and emerged on to London Bridge, where he was partially disarmed by a plain-clothes police officer.

[5] Former prisoner Usman Khan had been invited to the conference as a previous participant in the programme,[7] and although banned from entering London under the terms of his release, he was granted a one-day exemption to attend.

[12] Several fought back, including a Polish kitchen porter, Łukasz Koczocik, who fought Khan off with an ornamental spear,[13] a South African-born Londoner, Darryn Frost, who grabbed a 1.5-metre-long (4.9 ft) narwhal tusk from the wall to use as a weapon,[14] former prisoner John Crilly, and Steven Gallant, a convicted murderer attending the conference on day release from prison, after participating in the Learning Together programme.

[16] Several people were injured before members of the public, including a tour guide[17][18] and a plain-clothes British Transport Police officer, later seen walking away with a knife, restrained and disarmed Khan on the bridge.

[20][15] Armed officers of the City of London Police arrived at 14:03 and surrounded the attacker, who at the time was being restrained by a Ministry of Justice communications worker attending the rehabilitation meeting.

[25] A Transport for London bus which had stopped adjacent to the site of the shooting was found to have damage to both its front and rear windows, possibly caused, according to the Metropolitan Police, by a ricocheting bullet.

[41][42][43] Khan had been part of a plot, inspired by Al-Qaeda, to establish a terrorist camp on his family's land in Kashmir and bomb the London Stock Exchange.

[57] The Mayor of London, Sadiq Khan, thanked the emergency services and members of the public who helped to restrain the attacker, saying they had shown "breathtaking heroism".

[54][57] A parliamentary election hustings event scheduled to be held at Great St Mary's Church in Cambridge on 30 November was cancelled and replaced by a memorial vigil for the victims of the attack.

[59] In Pakistan, publication of Khan's Pakistani origins by the leading newspaper Dawn were deemed unpatriotic and defamatory, and led to demonstrations demanding that the publisher and the editor be hanged.

[63][64] A janaza prayer for Khan was held at a mosque in Birmingham, and he was buried in his family's ancestral village in Pakistan, following objections to his burial in the UK by local Muslims in his native Stoke.

[65] In 2021, following an inquest, Independent Reviewer of Terrorism Legislation Jonathan Hall QC called for those involved in the planning or preparation of terrorist attacks to be given automatic life sentences.

[13] In October 2020, Gallant was granted the royal prerogative of mercy by the Queen on the advice of Lord Chancellor Robert Buckland, in order to bring his parole hearing forward by ten months to June 2021.

[74] On 28 May 2021, the jury concluded the victims had been unlawfully killed and that insufficient monitoring of Khan, unreasonable belief in his rehabilitation, a lack of information sharing between agencies, and inadequate security planning at the event were all contributing factors in their deaths.