The Manchester Arena attack, in which 22 people were killed, was underpinned by authorities’ failure to assess and address the threat posed by terrorists returning to Britain from Libya, an inquiry has found.
And the chief of MI5 made an unprecedented public apology as he acknowledged the security service did not seize the “slim” chance it had of thwarting the Manchester Arena terror attack.
Suicide bomber Salman Abedi, 22, and his brother Hashem, 25 — who was sentenced to life in jail for his role in plotting the 2017 attack — had visited Libya during the civil war there in 2011 and were probably involved in the fighting, inquiry chairman Sir John Saunders said.
The brothers were radicalised in Libya and had probably received training or assistance in building the bomb used in the attack, the inquiry report said.
MI5 pledges improvements
"Having examined all the evidence, the chair of the inquiry has found that 'there was a realistic possibility that actionable intelligence could have been obtained, which might have led to actions preventing the attack'," MI5 director general Ken McCallum said.
"I deeply regret that such intelligence was not obtained.
"To all those whose lives were forever changed on that awful night, I am so sorry that MI5 did not prevent the attack at the Manchester Arena."
Despite a regional assessment conducted by the Joint Terrorism Analysis Centre in 2010 accurately predicting the potential danger posed by young Libyan-linked people who may have been influenced by extremist groups such as the Libyan Islamic Fighting Group, a focus was instead placed on those returning from Syria, which meant that the risk from Libya was played down, the report said.
Speaking to bereaved families gathered at Manchester Hall, Sir John said: "I have concluded that there were a number of contributory factors to Salman Abedi's radicalisation.
"His family background and his parents' extremist views, along with their participation in the struggle in Libya, played a significant part.
"During the time Salman Abedi and Hashem Abedi spent in Libya, during which they were probably involved in fighting, they are likely to have come into contact with a number of violent extremists.”
Security services and counter-terrorism police should have learnt from the situation in Libya and taken precautions in relation to the threat to UK national security from people returning from all conflict zones, Sir John said.
While it is acknowledged that investigating every person returning from Libya would have been impractical, the threshold selected by British intelligence agencies was insufficiently nuanced, the report suggested, and there should have been particular indicators that would have caused some people returning from Libya to be treated with concern.
Mr McCallum added: "Gathering covert intelligence is difficult — but had we managed to seize the slim chance we had, those impacted might not have experienced such appalling loss and trauma. I am profoundly sorry that MI5 did not prevent the attack.
"The people of MI5 and our policing partners come to work every day to stop terrorism. We continually work to improve the counter-terrorism system; since the terrible events of 2017, we have made more than 100 improvements. But we are determined to do more.
"Where there are opportunities to strengthen the UK's defences further, MI5 will act. We will continue to do everything in our power to keep our country safe from hidden threats. MI5 exists to stop atrocities."
Abedi was recorded as a subject of interest in 2014 and investigated by MI5 but later deemed “low risk”.
He was identified on six occasions as a contact of suspected extremists between 2013 and 2017.
The security service investigates about 3,000 active subjects when it believes someone may pose a threat, and has about 600 live investigations at any one time. Significant numbers of SOIs are overseas.
They are ranked by priority and resources will be dedicated to them depending on the level of threat they are judged to pose.
When they are no longer deemed to pose a threat, they are downgraded and marked as a “closed” subject, joining a list of around 40,000 people who have at some point featured in probes.
Mr McCallum did not take questions on the findings but in his recorded statement said that since the attack MI5 has made “more than 100 improvements” as it “continually” works to better efforts to fight terrorism.
Neither MI5 nor the Home Office would say whether anyone at the security service had faced disciplinary action.
MI5 and the police disrupted at least 37 late-stage terror attack plots since the start of 2017.
“I am committed to working with MI5, policing and partners to study the recommendations. Together we will do everything possible to prevent a repeat of this horrifying attack," Home Secretary Suella Braverman said.
Security Minister Tom Tugendhat said he shared the “sorrow” expressed by MI5, adding: “I know that all of us are working to make sure that the improvements that need to be made are made.”
Who is Salman Abedi?
Salman Abedi, a British man of Libyan descent, was born in Manchester in 1994, and grew up in a family with strong ties to Libya.
Abedi had visited during the Libyan civil war and was believed to have received training or help in building a bomb while he was there.
Their father, Ramadan Abedi, had made clear his support for suicide attacks in the Libya conflict on Facebook.
Salman and Hashem were rescued by the Royal Navy from Libya in 2014.
Before the suicide bombing, Salman Abedi was known to security services but was not considered an imminent threat. He died in the explosion at the arena.
