Update 2: The prime minister's office of Turkey now says "it is understood" that Syria shot down its Turkish fighter jet, reports Reuters and the BBC. Previously, Prime Minister Erdogan had said he couldn't confirm that Syrian officials shot down the Turkish warplane after reports emerged citing Turkish officials and witnesses accusing Syria of shooting down the plane.

Update 1: Despite reports from Turkish officials and witnesses that Syria shot down a Turkish warplane, Turkish Prime Minister Tayyip Erdogan told reporters at a news conference he couldn't confirm that Syrian officials shot down the 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 said, according to NBC News. He did not rule out the possibility that Syria shot it down.

Neighborly relations between Syria and Turkey were already deteriorating, and now Syria has downed a Turkish war plane, according to reports. Earlier Friday, the plane had been reported missing, and Turkish Prime Minister Tayyip Erdogan later reportedly said Syria admitted to shooting down the F-4 phantom and has apologized. It's not yet clear how Turkey is going to respond to the incident but the country went on high alert, calling an emergency security meeting, according to Reuters' Oliver Holmes:

Turkish officials said Erdogan, who was returning to Ankara from Brazil on Friday evening, would convene a security meeting with the interior and foreign ministers and the chief of general staff. They did not say what would be discussed.

Turkey said earlier it had lost contact with one of its military aircraft off its south-eastern coast after it took off from Erhac airport in the eastern province of Malatya. 

A Turkish official confirmed to local newspaper the Hurriyet Daily that the plane was shot down by Syria but that the pilots, who are in good health, were rescued from the Mediterranean Sea. The BBC managed to get accounts from witnesses:

Witnesses in the Syrian coastal city of Latakia meanwhile told BBC Arabic that Syrian air defences had shot down an unidentified aircraft near the town of Ras al-Basit.

Lebanon's al-Manar television channel - controlled by Lebanon's Shia Hezbollah movement, an ally of the Syrian government - also reported that Syrian security sources had said that "Syrian air defences shot down a Turkish warplane and hit another in Syrian airspace".

The incident is immediately being cast against the backdrop of Syria's ongoing civil war which has driven the two countries apart despite reasonably warm relations in the past. The NATO ally has proposed establishing safe havens inside Syria involving military intervention but Syria and its allies China and Russia have strongly-opposed such an intervention. If that weren't reason enough for Syria to be angry with Turkey, it was reported yesterday that the CIA is helping direct weapons purchased by Turkey to opposition groups in the country.