Carrying a large backpack, he detonated an improvised explosive device containing triacetone triperoxide (TATP) and nuts and bolts serving as shrapnel.

Grande briefly suspended her tour and hosted a benefit concert on 4 June entitled One Love Manchester, raising a total of £17 million towards victims of the bombing.

Abedi's sister said her brother was motivated by the injustice of Muslim children dying in bombings stemming from the American-led intervention in the Syrian civil war.

Police uncovered photographs with the brothers alongside the sons of Abu Anas al-Libi, a high ranking Al-Qaeda fighter in Libya.

[6] Then French interior minister Gérard Collomb said in an interview with BFM TV that Abedi may have been to Syria, and had ‘proven’ links with ISIS.

On 18 May, at 18:14, CCTV footage first identified him leaving the Shudehill Interchange, briefly talking to a Manchester Arena worker before observing the queues and entrances within the City Room.

Images released by The New York Times show an explosive charge inside a lightweight metal container which was carried within a black vest or a blue Karrimor backpack.

His torso was propelled by the blast through the doors to the arena, possibly indicating that the explosive charge was held in the backpack and blew him forward on detonation.

[29] The explosion killed the attacker and 22 concert-goers and parents who were in the entrance waiting to pick up their children following the show; 119 people were initially reported as injured.

[37][38] Within a minute of the bombing, a police constable sent a radio message saying ‘We need more people at Victoria, we just had a loud bang’, through the BTP channel.

BTP's command centre called for the North West Ambulance Service (NWAS) and the Greater Manchester Police (GMP).

The researchers suggested that May's gender played a role in the public's response, writing that female leaders ‘cannot count on rallies following major terrorist attacks’.

[57] Thousands, joined by Rudd, Burnham and then Labour Party leader Jeremy Corbyn, gathered in Albert Square to remember the victims.

[60] The attack occurred two weeks before the 2017 United Kingdom general election; campaign funding for the Labour and Conservative parties was suspended.

[72] Three other men were arrested, and police initially spoke of a network supporting the bomber;[73] they later announced that Abedi had sourced all the bomb components himself and that they now believed he had largely acted alone.

[75] A total of 22 people were arrested in connection with the attack, but had all been released without charge by 11 June following the police's conclusion that Abedi was likely to have acted alone, even though others may have been aware of his plans.

[76] Within hours of the attack, Abedi's name and other information given confidentially to security services in the United States and France were leaked to the press, leading to condemnation from Home Secretary Amber Rudd.

[77][78] Following the publication of crime scene photographs of the backpack bomb used in the attack in the 24 May edition of The New York Times, United Kingdom counterterrorism police chiefs said the release of the material was detrimental to the investigation.

[82] The New York Times editor Dean Baquet declined to apologise for publishing the backpack bomb photographs, saying ‘We live in different press worlds’ and that the material was not classified at the highest level.

[87] On 18 October 2023, Coroner Sir John Saunders ruled that Salman Abedi's death was ‘suicide while undertaking a terror attack’.

The Kerslake Report was ‘an independent review into the preparedness for, and emergency response to, the Manchester Arena attack.’[89] In the report, Kerslake ‘largely praised’ the Greater Manchester Police and British Transport Police, and noted that it was ‘fortuitous’ that the North West Ambulance Service was unaware of the declaration of Operation Plato, a protocol under which all responders should have withdrawn from the arena in case of an active killer on the premises.

[90] However, it found that the Greater Manchester Fire and Rescue Service was ‘brought to a point of paralysis’ as their response was delayed for two hours due to poor communication between the firefighters' liaison officer and the police force.

[91][92][93] The report was critical of Vodafone for the ‘catastrophic failure’[94] of an emergency helpline hosted on a platform provided by Content Guru, saying that delays in getting information caused ‘significant stress and upset’ to families.

[114] The brothers were rescued from Tripoli by the Royal Navy survey ship HMS Enterprise in August 2014 as part of a group of 110 British citizens as the Libyan civil war erupted, taken to Malta and flown back to the UK.

[115][116] According to a retired European intelligence officer, speaking on condition of anonymity, Abedi met with members of the ISIS Battar brigade in Sabratha, Libya and continued to be in contact with the group upon his return to the UK.

[101] Manchester police believe Abedi used student loans to finance the plot, including travel overseas to learn bomb-making.

[122] He was known to British security services and police but was not regarded as a high risk, having been linked to petty crime but never flagged up for radical views.

[137] On 17 March, Hashem Abedi was found guilty on 22 charges of murder, on the grounds that he had helped his brother to source the materials used in the bombing and had assisted with the manufacture of the explosives which were used in the attack.

[143] Manchester Arena was closed until 9 September, when it opened with a benefit concert featuring Oasis songwriter Noel Gallagher alongside other acts from North West England.

[147] In October 2024 two survivors of the bombing won a harassment case, in the High Court, against former television producer Richard Hall, who had claimed without evidence that the attack was an ‘elaborate hoax’ by British government agencies and that no one was ‘genuinely injured’.