The drastic decline came after Israeli commandos raided a flotilla of aid ships, including the Mavi Marmara, a converted cruise liner, sailing to the Gaza Strip on May 31, killing nine Turkish activists.

The bloodshed delivered a huge blow to already fragile Turkish-Israeli ties, prompting Ankara to recall its ambassador and cancel joint war games with its long-time ally.

As Turks took to the streets in almost daily protests, Israel urged citizens on May 31 to avoid travelling to Turkey, although that warning was withdrawn on July 21.

Turkey and Israel had built a strong alliance after a 1996 military co-operation deal, but their relationship soured after sharp criticism from Ankara over Israel's devastating war on Gaza in late 2008 and early 2009.

The strain was reflected in 2009 tourism figures when only 311,582 Israeli tourists visited Turkey, compared to 558,183 in 2008, marking a decrease of 44.1 per cent.

Ship released

Israel released the Mavi Marmara, which it impounded after the raid, on Thursday with a Turkish tugboat towing the vessel out of Haifa port.

Two other Turkish vessels held there and in Ashdod port, the Defn-Y and the Gazze, will follow by Friday, Israeli and Turkish officials said.

Israel defended the marines' use of guns in brawls with Mavi Marmara passengers, who it said had endangered the soldiers' lives by attacking them with iron bars and knives.

But it waived a demand that the Turks sign undertakings not to sail again to Gaza, whose blockade it says curbs Palestinian gunrunning, for the vessels to be repatriated.

An Israeli official said the foreign ministry had instead sent Ankara "a message ... expressing Israel's expectation that Turkey will prevent other Turkish vessels from violating the naval blockade on the Gaza Strip".

"The message emphasises that Israel transfers equipment and goods to Gaza on an ongoing basis via the land crossings in a manner that is acceptable to the international community and which is anchored in recognised agreements," the official said.

A Turkish foreign ministry official had no immediate comment on Israel's request.

The official said the three Turkish vessels were expected to arrive in Turkey's Iskendurun port by August 9.

Israel still holds three non-Turkish vessels from the Gaza flotilla that was intercepted on May 31, as well as an Irish cargo ship, the Rachel Corrie, that sailed a few days later.