ANKARA - A Turkish prosecutor has prepared an indictment seeking 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, Turkish newspaper Sabah reported on Wednesday.Relations between the regional powers 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 UN report into the incident released last September largely exonerated the Jewish state.Sabah said it had seen details of the indictment prepared by Istanbul state prosecutor Mehmet Akif Ekinci and that it called for 10 life sentences to be given to each of the four commanders. It said the Istanbul chief prosecutor must approve the indictment before it is sent to the relevant court.The prosecutor could not immediately be reached for comment.The indictment was reported to accuse former IDF chief of staff Lt.-Gen. (res.) Gabi Ashkenazi and three other retired senior military commanders of involvement in the raid and refers to them as "fugitive suspects," Sabah reported.The 144-page indictment, it said, had been prepared after testimony from some 600 people, including 490 passengers from the six-ship flotilla and relatives of those who had died.Correspondence from the Turkish prime minister's office, the foreign and justice ministries and the intelligence service had also helped the prosecutor draw up the indictment, it said.In Jerusalem, an Israeli military spokeswoman had no immediate comment.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.The UN 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 while also finding 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.Israel said its marines had been attacked by activists wielding metal bars, clubs and knives when they boarded the Mavi Marmara and had opened fire in self-defense.Relations have been strained since the raid. Last week Turkey said it had scrambled military jets to intercept an Israeli plane that had violated northern Cypriot airspace and demanded an explanation. Israel declined to comment.Ankara is also involved in a long-running dispute with Israel and Cyprus over who has the right to drill for energy reserves in the eastern Mediterranean.