More than 250 survivors and relatives of victims of the suicide attack at an Ariana Grande concert in England in 2017 are suing MI5, the country’s domestic intelligence agency.
The attack, which occurred on May 22, 2017 at the Manchester Arena, left 22 people dead and more than 100 others injured.
A public inquiry published last year determined that MI5 might have had the opportunity to arrest suicide bomber Salman Abedi at Manchester Airport days before the massacre if it had discussed the information earlier.
“I discovered a significant missed opportunity to act that could have prevented the attack,” John Saunders, the former judge who led the investigation, said last year.
Abedi was a “subject of interest” to MI5 in 2014, but the agency closed his case because he was considered low risk.
Hashem Abedi, the attacker’s brother, was later sentenced to life in prison after being found guilty of helping to plan and carry out the bombing.
The investigation found that an officer had new intelligence about Abedi that saw him as a potential threat, but did not discuss it quickly enough with his colleagues.
The investigation prompted a rare public statement from MI5 chief Ken McCallum apologizing for the agency’s failure to “prevent the attack”.
Three law firms coordinated the collective complaint on behalf of survivors and their loved ones and submitted it to the Investigatory Powers Tribunal, an independent tribunal which investigates, among other things, alleged conduct by or on behalf of the services British intelligence.
No further information about the complaint could be released because it is an ongoing legal matter, the firms representing the victims said in a statement.
The complaint marks the first time MI5 has been prosecuted for failing to stop a terrorist attack, according to The Guardian.