NATO member Turkey today shot down a Russian war plane on the Syrian border, an act President Vladimir Putin said would have "serious consequences" for ties between two key protagonists in the Syria war.
The Turkish army said the plane was shot down by two F- 16s after violating Turkish airspace 10 times within a five- minute period, an account challenged by Moscow which said it was over Syria.
Turkish television pictures showed the jet exploding and crashing in a ball of flames into a Syrian mountain.
Turkish media said one pilot had been captured by rebel forces in Syria after both ejected by parachute while Syrian opposition sources said one was dead and another missing.
NATO has called an emergency meeting over the incident, the first of its kind since Russia launched air strikes in Syria in September, to the consternation of the West.
The presence of military aircraft from Russia, the United States, France, Turkey and a clutch of Gulf states in Syrian skies had long raised fears of an incident that could quickly escalate into a major diplomatic and military crisis.
The shooting down of the plane was "a stab in the back committed by accomplices of terrorists," Putin said at a meeting with Jordanian King Abdullah II in Moscow.
Putin said the plane fell in Syrian territory four kilometres from the border with Turkey and "did not in any way threaten Turkey".
"Today's tragic event will have serious consequences for Russian-Turkish relations," he warned.
The Turkish army said the downing took place over the Yayladagi district of Turkey's Hatay province on the border with Syria.
"The plane violated Turkish air space 10 times in five minutes despite warnings," the army said in a statement, adding it was shot down at 1234 IST "according to the rules of engagement".