"We are not afraid," Irish Nobel Peace Prize winner Mairead Maguire told Ireland's RTE state radio by satellite phone from aboard the aid-laden ship on Friday.

"We started out to deliver this cargo to the people of Gaza and to break the siege of Gaza, that is what we want to do," the 66-year-old said as the vessel steamed toward the Hamas-run Palestinian enclave.

The MV Rachel Corrie was just hours from Gaza but the 15 aboard — Irish and Malaysian activists, four Indonesian crew and a Scottish captain — did not intend to leave international waters and run the Israeli gauntlet until after daybreak Saturday, organizers said.

With Ireland's prime minister warning sternly that the ship must be allowed to reach Gaza, the activists have put Israel in a tight spot at a time when it already faces a serious diplomatic crisis over Monday's botched raid in which its soldiers killed eight Turks and an American of Turkish descent aboard a Gaza-bound flotilla.

Israeli Prime Minister Benjamin Netanyahu told his Cabinet on Thursday night that the boat would not reach the territory. On Friday, Israel's Foreign Minister Avigdor Lieberman repeated the resolve. "We will stop the ship, and also any other ship that will try to harm Israeli sovereignty. There is no chance the Rachel Corrie will reach the coast of Gaza," Lieberman told Israel's Channel 1 television.

The vessel is named for an American college student who was crushed to death in 2003 by a bulldozer while protesting Israeli house demolitions in Gaza.

Turkey's Prime Minister Recep Tayyip Erdogan accused Israel of betraying its religion as Palestinian flags flew at the funeral of a Turkish activist. Addressing supporters of his AK Party in the central Anatolian city of Konya, Erdogan said: "You (Israel) killed 19-year-old Furkan Dogan brutally. Which faith, which holy book can be an excuse for killing him?

"I am speaking to them in their own language. The sixth commandment says 'Thou shalt not kill'. Did you not understand? I'll say again. I say in English, 'You shall not kill'. Did you still not understand? So I'll say to you in your own language. I say in Hebrew 'Lo Tirtzakh'."

Pledging never to forsake the Palestinian people, Erdogan likened the Israeli killings of Palestinians to Turkish civilian deaths caused by conflict with Kurdish separatist militants. He went on to stand up for the Palestinian Hamas government.

"Hamas are resistance fighters fighting for their land, they are Palestinians. They won an election and now they are in Israel's prisons. I told this to the Americans, that I do not accept Hamas as a terrorist group."

In Istanbul, a crowd of some 10,000 people held prayers for a journalist among the dead. Chants of "murderer Israel" echoed across the courtyard of the historic Beyazit Mosque, where a huge banner called for the Israeli Embassy to be shut down.

Turkish President Abdullah Gul has warned relations with Israel "will never be the same" and Deputy Prime Minister Bulent Arinc said economic and defense ties will be slashed. "We may plan to reduce our relations with Israel to a minimum," Arinc said. "But to assume everything involving another country is stopped in an instant, to say we have crossed you out of our address book, is not the custom of our state."

International condemnation continued Friday, with protests in Syria, Greece, Bahrain and Malaysia, where some demonstrators burned Israeli flags and carried mock coffins. In Norway, the military canceled a seminar scheduled for later this month because an Israeli Army officer was to have lectured.