Israel will not face action from the International Criminal Court (ICC) over its raid on the Mavi Marmara, one of the vessels in a flotilla bound for the blockaded territory of Gaza in 2010.

Nine activists from Turkey were killed by Israeli commandos after the soldiers descended by rope from helicopters. The commandos opened fire after clashes broke out the event led to widespread criticism of Israel's actions.

The ICC investigation was launched in May this year after representations from the Union of the Comoros. However, its chief prosecutor, Fatou Bensouda, said in a statement released today that though she had "concluded that there is a reasonable basis to believe that war crimes under the jurisdiction of the International Criminal Court" were committed on board the Mavi Marmara, she had concluded that "the potential case(s) likely arising from an investigation into this incident would not be of 'sufficient gravity' to justify further action by the ICC."

She added: "Without in any way minimising the impact of the alleged crimes on the victims and their families, I have to be guided by the Rome Statute, in accordance with which, the ICC shall prioritise war crimes committed on a large scale or pursuant to a plan or policy."

A UN report in September 2011 chaired by Sir Geoffrey Palmer criticised the action of the flotilla, saying that it acted "recklessly" in trying to breach the blockade and warning that "there exist serious questions about the conduct, true nature and objectives of the flotilla organisers".

However, it also said: "The loss of life and injuries resulting from the use of force by Israeli forces during the take-over of the Mavi Marmara was unacceptable. Nine passengers were killed and many others seriously wounded by Israeli forces. No satisfactory explanation has been provided to the Panel by Israel for any of the nine deaths. Forensic evidence showing that most of the deceased were shot multiple times, including in the back, or at close range has not been adequately accounted for in the material presented by Israel."

The ICC began work in 2002 and sits in the Hague, in the Netherlands.