Over 250 survivors and relatives of the 2017 Manchester Arena bombing have filed a lawsuit against MI5.

The lawsuit claims MI5 failed to act on information that could have prevented the attack that resulted in 22 deaths and over 100 injuries.

An official investigation criticized MI5 for slow response to crucial information and missing an opportunity to thwart the attack.

The attacker was known to MI5 since 2014 but was not pursued due to being deemed low-risk at the time.

A group claim has been submitted to the Investigatory Powers Tribunal with a hearing anticipated early next year.

MI5's head, Ken McCallum, has issued a public apology for the agency's shortcomings in preventing the tragedy.

MI5 is currently not commenting on the legal case that is in progress.