Turkey called an extraordinary meeting of NATO while Russian Foreign Minister Sergei Lavrov said he had scrapped a planned trip to Turkey tomorrow aimed at narrowing differences on the Syria conflict.
The Turkish army said the plane was shot down by two of its F-16s after it violated Turkish airspace 10 times within a five-minute period, an assertion backed up by its NATO ally the United States.
Turkish television pictures showed the Su-24 exploding and crashing in a ball of flames into a Syrian mountain and two pilots parachuting to the ground after ejecting.
Their fate was uncertain, with reports one had been killed.
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The incident was the first of its kind since Russia launched air strikes in Syria in September in support of President Bashar al-Assad's regime, causing concern in the West over a possible clash with US-led coalition planes also in the skies.
Putin branded the shooting down of the aircraft a "stab in the back committed by accomplices of terrorists".
Putin said the plane fell in Syrian territory four kilometres from the border and "did not in any way threaten Turkey".
The Turkish army said the downing took place over the Yayladagi district of Hatay province on the border with Syria.
"The plane violated Turkish air space 10 times in five minutes despite warnings," it said in a statement, adding that it was shot down at 0724 GMT "according to the rules of engagement".
while Ankara summoned Moscow's charge d'affaires to the foreign ministry.
"Everyone must know that it is our international right and national duty to take any measure against whoever violates our air or land borders," Turkish Prime Minister Ahmet Davutoglu said.
CNN-Turk television said Syrian Turkmen forces fighting the Damascus regime had captured one of the pilots while Syrian opposition sources told AFP one had been killed by rebels and the second was missing.
Turkey's Dogan news agency broadcast footage of what it said was Russian helicopters flying over Syrian territory in an apparent search for the lost men.
Turkey has expressed anger at the operation, saying it is aimed at buttressing the Syrian regime and has displaced thousands of Turkmen Syrians, an ethnic minority in the area and strong allies of Ankara.
Russia however insists its strikes are aimed against Islamic State jihadists.
European Union President Donald Tusk warned of a "dangerous moment", saying "all should remain cool headed and calm."
At Ankara's request, NATO allies will hold an "extraordinary" meeting at 1600 GMT to discuss the incident.
Russian fighter jets entered Turkish airspace in two separate incidents in October, prompting Ankara to summon the Russian ambassador twice in protest.
Turkey and Russia have long been at loggerheads over the Syrian conflict, with Ankara seeking Assad's overthrow while Moscow does everything to keep him in power.
The Turkish military in October also shot down a Russian-made drone that had entered its airspace. But Moscow denied the drone belonged to its forces.
As well as cancelling his visit to Turkey, Lavrov warned Russian citizens against travel to the country, which would be a huge blow for the Turkish tourism industry.