Eleven Ukrainian sailors are missing after a ship sank off Lebanon, and UN forces with the help of Israel's military have launched a rescue operation, Israeli officials said yesterday.

"Defence Minister Ehud Barak instructed the Israeli navy and air force to help search for missing people on the ship that sank off the coast of the Lebanese port of Tyre," the defence ministry said in a statement.

One Ukrainian crew member has so far been rescued from the cargo ship that sailed from Greece, but 11 of his compatriots are still missing, it said, adding that Israeli helicopters were involved in the search.

An army spokeswoman said the Israeli military was helping the UN Interim Force in Lebanon with the search.

UNIFIL deputy spokesman Andrea Tenenti told AFP in Beirut that a distress signal was received from the Togolese-flagged vessel late on Friday.

"When a boat from the Turkish MTF (Maritime Task Force) arrived there, the vessel was already sinking. We saved one sailor," he said.

The ship had been heading towards the northern Israeli port of Haifa and was 50 miles off the Lebanese coast in international waters when it sank, the Israeli military spokeswoman said.

A Lebanese military spokesman confirmed to AFP that the vessel went down in international waters, saying it sank "more than 70 miles off Naqura" on the Lebanon-Israel border.