There has been sharp international criticism of the military action by Israel in seizing an aid convoy of foreign ships that tried to break through the Israeli naval cordon to reach Gaza.
At least 10 rights activists were killed in fighting that broke out when Israeli commandos boarded some of the ships.
Turkey, which has long had friendly relations
with Israel, was among the first countries to denounce the Israeli interception.
Turkish Foreign Ministry Deputy Undersecretary Selim Yenel told RFE/RL that Israel's ambassador had been warned about "irreversible damage" to bilateral relations. He rejected Israeli claims that the Turkish ships, which had been inspected by the NATO country, may have been smuggling weapons.
"This happened in international waters, and this was a gross violation of international law," Yenel said. "We have called in the Israeli ambassador here. We said that this was a gross violation of international law because this was a convoy carrying only humanitarian goods. [It was] a peaceful initiative, and this cannot be accepted at all."
Israeli soldiers unload wounded from the ships to stretchers as they arrive at a Tel Aviv hospital.
Most of the hundreds of rights activists aboard the six vessels of the convoy were Turkish, and the flotilla mainly consisted of Turkish-flagged ships. The 10 or more activists who were killed were mostly Turks too, according to reports.
Yenel said Turkey was withdrawing its ambassador from Israel and had called for an emergency meeting of the UN Security Council. Lebanon, the current council president, later called an emergency council meeting on the crisis for later on May 31.Regret, Condemnation
In Istanbul, tens of thousands of demonstrators took to the streets in protest. Earlier, police struggled to hold back an angry crowd who stormed the gates of the Israeli consulate there.
In Brussels, ambassadors from the 27-member European Union are to hold an emergency meeting later today to discuss the incident.
EU foreign-policy chief Catherine Ashton said she had spoken to Israeli Foreign Minister Avigdor Lieberman and "expressed our deepest concern about the tragedy that has happened. I have said there should be an immediate inquiry by Israel."
UN Secretary-General Ban Ki-moon said he was "shocked" and he also called for a full investigation.
In the United States, White House spokesman William Burton expressed "deep regrets" over the loss of life.
Palestinian Authority President Mahmud Abbas declared three days of mourning, and Arab League chief Amr Musa called the raid a crime against a humanitarian mission and called for an emergency meeting of the Arab League.Differing Accounts
Each side has given conflicting accounts of the dramatic early-morning raid and the clashes that followed.
A demonstrator waves a Palestinian flag during a protest in front of the Israeli Consulate in Istanbul.
The main organizers, the Free Gaza Movement, said the commandos "began to shoot the moment their feet hit the deck" and accused them of firing directly at sleeping civilians.
"We were a flotilla of six civilian ships and at about 4:30 this morning Israeli 'commandos,' if that’s what you want to call them, rappelled down off a helicopter and landed at least on the deck of the Turkish [ship], not sure about the other one, looked around and started to shoot at us," the movement's Greta Berlin told RFE/RL
But Israel says it was the activists who attacked first, with "live fire" as well as knives, before its forces opened fire.'Armada Of Hate'
At a Jerusalem news conference, Israeli Deputy Foreign Minister Danny Ayalon took a hard line in defense of Israel's actions.
"The armada of hate and violence in support of the Hamas terror organization was a premeditated and outrageous provocation," Ayalon said. "The organizers are well-known for their ties to global jihad, Al-Qaeda, and Hamas. They have a history of arms smuggling and deadly terror."
Ayalon defended the four-year-old sea blockade of Gaza as legal, because the ruling Hamas organization there are terrorists. Hamas reacted by calling the Israeli raid a crime.
"We in Hamas consider the Israeli attack on the freedom flotilla to be a great crime and a flagrant violation of international law," Hamas spokesman Sami Abu Zuhri told Reuters in Gaza City.
"In spite of the great damages suffered by the people in solidarity on board this fleet, we consider that this fleet's message has been delivered".
Israeli Prime Minister Binyamin Netanyahu, who is currently visiting Canada, said he was postponing a scheduled visit to Washington to return to Israel.written by Breffni O'Rourke, with contributions from RFE/RL correspondent Robert Tait, Anna Zamejc of RFE/RL's Azerbaijani Service, and agency reports