Turkey's Prime Minister Recep Tayyip Erdogan.

Ankara - A Turkish court has approved an indictment seeking multiple life sentences for four former Israeli military commanders over their alleged involvement in the 2010 killing of nine Turks on a Gaza-bound aid ship, state media reported on Monday.

The indictment, prepared by Istanbul state prosecutor Mehmet Akif Ekinci, was submitted to the court last week and its approval effectively marks the start of a trial in absentia against the four men.

Relations between Turkey and Israel deteriorated sharply after Israeli commandos raided the Mavi Marmara aid vessel in May 2010 to enforce a naval blockade of the Gaza Strip and killed nine Turks in clashes with activists on board the ship.

Turkey expelled Israel's ambassador and froze all military cooperation after a U.N. report into the incident released last September largely exonerated the Jewish state.

The indictment accuses Israel's former Chief of General Staff Gabi Ashkenazi and three other retired senior military commanders of involvement in the raid and calls for between 8 000 and 18 000 life sentences for each of the men, state news agency Anatolian said on its website.

The Israeli military has not commented on the indictment.

Turkey had previously said it would try to prosecute all Israelis responsible for crimes committed during the raid and the prosecutor had written to Israel seeking the names of those involved but had received no answer.

Last week a Turkish lawyer representing victims of the raid said Israel had offered to pay $6 million in compensation in turn for lawsuits to be dropped.

However, a senior Israeli official who declined to be named said Israel, having indicated last year that it was prepared to indemnify victims without accepting blame, had not renewed its offer.

The U.N. report into the raid last September was meant to encourage a rapprochement between the two countries but ultimately deepened the rift when it concluded Israel had used unreasonable force but that the blockade on Gaza was legal.

Turkey was stung by Israel's refusal to make a formal apology and pay compensation to families of the dead. - Reuters