The Moldovan-flagged ship chartered by a charity run by the son of Libyan leader Col Muammar Gaddafi, left a Greek port on Saturday.

Israel asked for help from the UN, and had talks with Greece and Moldova. But organisers insist they will go to Gaza.

An Israeli raid on a Gaza-bound ship in May killed nine Turkish activists.

Israel insisted its troops were defending themselves but the raid sparked international condemnation.

Israel recently eased its blockade, allowing in almost all consumer goods but maintaining a "blacklist" of some items.

Israel says its blockade of the Palestinian territory is needed to prevent the supply of weapons to the Hamas militant group which controls Gaza.