Four Israeli ex-military chiefs went on trial in absentia in an Istanbul court on Tuesday over a deadly 2010 raid on a Gaza-bound Turkish ship in what Israel branded a "show trial" by its former ally.
Hundreds of protesters gathered outside the Istanbul court waving Palestinian flags and chanting "Damn Israel" as the trial opened.
Prosecutors are seeking life sentences for the four over the night-time assault in international waters in the Mediterranean Sea that plunged relations between Israel and Turkey into deep crisis.
Israeli commandos boarded the Turkish-flagged Mavi Marmara, the largest ship in a flotilla dispatched by Turkish relief agency IHH to break Israel's blockade of the impoverished Gaza Strip, on 31 May, 2010, leaving nine Turkish activists dead.
The defendants are former military chief of staff Gaby Ashkenazi, former navy chief Eliezer Marom, former military intelligence head Amos Yadlin and former air force intelligence chief Avishai Levy.
They did not appear in the dock, after Israel ruled that those who took part in the raid did nothing wrong, and one of the lawyers for the plaintiffs said they expected the court to issue an arrest warrant for the men.
"This is not a trial but a show trial and has nothing to do with law and justice," Israeli foreign ministry spokesman Yigal Palmor told AFP, saying the defendants had not even been informed about the nature of the charges.
"They haven't been given even a symbolic chance to have legal representation," he added.
"It's a propaganda showcase. The government of Turkey, if it really wanted to do something about this issue, would engage with Israel."
Last year, an Israeli probe ruled that the raid did not violate international law, in a finding that Turkey, once its closest Muslim ally, said lacked credibility.
A UN report in September 2011 found Israel had used "excessive" force in the raid, but also said Israel's blockade of Gaza was legal and that the flotilla organisers had acted "recklessly" in attempting the mission.
The raid triggered a crisis between Israel and Turkey and resulted in a dramatic downgrade in diplomatic relations and the expulsion of the Israeli ambassador from Turkey. Military ties were also cut.
There have been several other attempts to reach the Palestinian territory by boat, all of which have been stopped by Israel, although there has been no repeat of the bloodshed.
"Today only four Israeli commanders are standing trial but this case could have a political extension," said Humanitarian Relief Foundation (IHH) vice-chairman Huseyin Oruc. "The court has all the evidence."
In May, Israeli Deputy Foreign Minister Danny Ayalon had said he was expecting foreign diplomatic pressure on Turkey to stop the trial, saying it could have "wide-ranging implications for NATO and US forces," which frequently board ships suspected of terror activity.
Turkey insists ties will not return to normal unless Israel offers a formal apology, compensates the victims and lifts the blockade on the impoverished Gaza Strip.
Busloads of demonstrators poured in from across the country to protest outside the court.
Protesters carrying Palestinian flags chanted "Allahu Akbar" (God is great)" and "Damn Israel" while some wore headbands declaring "Until Palestine is free," and unfurled banners saying "Martyrs are here, where are the Zionists?"
A giant balloon with the words "Israel on trial" emblazoned across it was flying in the air above the court.
"We are here to witness history," said Mehmet Cinar, a member of IHH. "Israel is standing trial for the first time in another country."
Turkish journalist Ali Ebubekir Topcan, who was aboard the Mavi Marmara when it came under attack, said he was subjected to "inhuman treatment" by the Israeli commandos.
"All my journalism materials and archives were seized by Israeli soldiers who are still holding them," he said.
An activist aboard another vessel in the flotilla, retired US army colonel Ann Wright, was also due to testify about her experience.
"It is very important to be here for the first time before the court of law where the evidence is being presented for what we believe are Israeli crimes," she told reporters.
Last month, Israeli troops boarded a Finnish-flagged ship after it tried to breach Israel's tight maritime embargo on Gaza, which prohibits all naval traffic in and out of the densely populated coastal territory.