Turkey is ready to try four Israeli commanders held responsible for the killing of nine Turkish activists in a 2010 raid on a Gaza-bound aid flotilla, Anatolia news agency reported Monday.

An Istanbul court unanimously approved an indictment finalised Wednesday by Turkish prosecutors, who want life sentences for the Israelis for their alleged role in the deadly flotilla raid, the agency said.

Israeli commandos boarded the Turkish-flagged Mavi Marmara, the largest ship in a flotilla aimed at breaking Israel's Gaza blockade, on May 31, 2010, leaving nine pro-Palestinian activists dead.

The raid triggered a crisis between Israel and Turkey, once regional allies, and resulted in a dramatic downgrade in diplomatic relations and expelling of the Israeli ambassador from Turkey. Military ties were also cut.

The 144-page indictment called for nine life sentences to be given to each of the four commanders, including Israel's former chief of the general staff Gabi Ashkenazi.

The date for the trial is not yet announced, but it would be held in the absence of the accused, Israel having ruled out any prosecution of those who took part in the attack.

A United Nations report into the raid last September accused Israel of acting with "excessive force" in the operation.