Survivors of the 2017 Ariana Grande concert bombing have launched a lawsuit against Britain's intelligence agency.

LONDON (AP) – More than 250 survivors of the 2017 Ariana Grande concert bombing in Manchester, England, that killed 22 people, are suing Britain's domestic intelligence agency, lawyers said.

Lawyers from three law firms announced on Sunday that they had filed a class-action lawsuit on behalf of more than 250 clients at the UK's Investigatory Powers Tribunal. They said they could not provide further details as it was a legal matter.

At the end of Grande's concert on May 22, 2017, as thousands of young fans were leaving, suicide bomber Salman Abedi planted a bag bomb at the Manchester Arena. More than 100 people were injured, most of them children and teenagers. Abedi died in the explosion.

An official inquiry last year said Britain's domestic intelligence agency, MI5, failed to act quickly on key information and missed a crucial opportunity to prevent the blast, Britain's deadliest extremist attack in years.

Abedi was a “subject of interest” to MI5 officials in 2014, but his case was soon closed as it was deemed low risk.

The report also admitted that one MI5 officer believed the information about Abedi was a potential national security issue, but did not immediately discuss it with colleagues.

MI5 chief Ken McCallum said in a rare televised statement that his agency “deeply regrets” the failure to prevent the attack.

Associated Press