BEIRUT: Turkey lost a warplane over the Mediterranean on Friday, but its prime minister said he could not confirm reports that Syria had shot it down and had apologized.

If the Syrians did indeed bring down the Turkish F-4 jet, a new crisis could erupt between two prickly Middle Eastern neighbors already at bitter odds over a 16-month-old revolt against Syrian President Bashar al-Assad.

However, in his first public comments on the warplane's loss,Turkish Prime Minister Tayyip Erdogan took a measured tone, telling reporters he could not say whether the plane had crashed or been shot down.

He said he had no word on the fate of the two airmen.

"The chief of general staff has made the necessary statement about the missing plane. I am not saying it was brought down at the point it fell. It is not possible to say this without knowing the exact facts," Erdogan told a news conference.

The Turkish military earlier said one of its planes was missing. Erdogan said Turkish ships and helicopters were searching for the airmen in cooperation with Syrian vessels.

The prime minister spoke for 15 minutes about trips he had just completed to Mexico and Brazil before mentioning the loss of the plane in response to a question.

Erdogan said he had no firm information on a reported Syrian apology and promised a further statement after a security meeting with his interior and foreign ministers and the chief of general staff later in the evening.

NATO-member Turkey, which had drawn close to Syria before the uprising against Assad, turned against the Syrian leader when he responded violently to pro-democracy protests inspired by popular upheavals elsewhere in the Arab world.

Ankara has previously floated the possibility of setting up some kind of safe haven or humanitarian corridor inside Syria, which would entail military intervention, but has said it would undertake no such action without U.N. Security Council approval.

Turkey hosts about 32,000 Syrian refugees and allows the rebel Syrian Free Army to operate from its territory.

The news that Syrian air defenses downed the plane was first reported by Al-Mayadeen, a Lebanon-based television channel launched this month that hopes to counter the influence of Arabic-language satellite stations such as Al-Jazeera and Al-Arabiya, both funded by Sunni Gulf Arab countries that have backed the revolt against Assad.

Russia and China, Assad's strongest backers abroad, have fiercely opposed any outside interference in the Syrian crisis, saying envoy Kofi Annan's peace plan is the only way forward.

Russian Foreign Minister Sergei Lavrov said after talks with his Syrian counterpart that he had urged Syria to "do a lot more" to implement Annan's U.N.-backed proposals, but that foreign countries must also press rebels to stop the violence.

Lavrov said the Syrian authorities were ready to withdraw troops from cities "simultaneously" with rebels. A Syrian military pullback and a ceasefire were key elements in Annan's six-point peace plan, most of which remains a dead letter. (Reuters)