A ship carrying aid for Palestinians blockaded in Gaza by Israel left Greece on Saturday, just over a month after nine activists died in an Israeli raid on an aid flotilla on a similar mission.

Organisers said the Moldovan-flagged boat, with 12 crew and up to ten activists on board, would head for Gaza but would go to the Egyptian port of El Arish instead if banned from reaching their destination.

"We hope the Israelis will not ban the ship from entering the port of Gaza. If they decide to do so we have no means to object to that. This is a peaceful mission," said Youssef Sawani, executive director of the Libyan charity organising the aid trip.

"Our sole goal and intention is to have the goods delivered to those who need it. It's not to make an event or a show in high seas or somewhere else," he said before the ship left the Greek port of Lavrio.

A charity chaired by the Libyan leader's son Saif al-Islam Gaddafi is organising the trip and said the ship carried some 2,000 tons of food and medicine and complied with international rules. The trip was expected to take between 70 and 80 hours.

Nine pro-Palestinian activists died in May when Israeli marines stormed a Turkish aid ship leading a Gaza-bound convoy, prompting an international outcry.

Israel said its commandoes were attacked with knives and sticks when they boarded the ship and acted in self-defence. Israel said on Saturday it contacted Greek, Egyptian and Moldovan authorities to make sure the ship chartered by the Gaddafi International Charity and Development Foundation would not attempt to reach Gaza.

Its ambassador to the United Nations sent letters to UN Secretary-General Ban Ki-moon and the president of the UN General Assembly, Ali Treki of Libya.

"In spite of the stated intention of this mission, we are deeply concerned that the true nature of its actions remains dubious," Gabriela Shalev wrote. "This mission is completely unwarranted," she wrote, urging the international community to ensure that the ship "does not sail".

The organisers said the Amalthea, re-named Hope, carried only food and medicine and complied with international rules.

Supporters of the charity making the trip were mostly Libyans, they said, with also one Nigerian and a Moroccan. The crew include Cubans, Haitians, Syrians and Indians.

Israel says its blockade of Gaza is necessary to stop arms and materials it fears could be used for military purposes from reaching Gaza's Hamas Islamist rulers.

The UN says the blockade has led to a humanitarian crisis for the territory's 1.5 million people, of whom about 1 million depend to some extent on regular supplies of UN and other foreign aid brought in overland after Israeli inspection.

Following the international outrage caused by its raid on the aid flotilla, Israel has announced steps to ease the blockade of the enclave and set up an inquiry into the incident.-Reuters