The bodies were flown from Israel to Istanbul, along with more than 450 activists, to a heroes' welcome.
Israel has said there is no need for an international inquiry into the incident, insisting its own will meet the "highest international standards".
The UN Human Rights Council (HRC) voted earlier to set up an investigation.
Israeli Prime Minister Benjamin Netanyahu has said his troops had no choice but to stop the ships.
He argued the flotilla had been aiming not to deliver humanitarian aid to Gazans, but to break Israel's blockade.
It was Israel's duty to prevent rockets and other weapons being smuggled into Gaza to Hamas by Iran and others, he said.
Turkey, one of Israel's few allies in the Muslim world, recalled its ambassador after the incident on Monday.
