One Russian pilot of a warplane downed by Turkey over Syria on Tuesday was killed by rebels and the second is missing after they both parachuted, rebel and opposition sources said.

A Russian helicopter was also blown up by rebels following an emergency landing in government-held territory after it was damaged by rebel fire, but its crew was able to escape, a monitor said.

The sources told AFP that the first pilot of the downed warplane was killed by opposition forces who shot at him as he landed after ejecting.

Several videos circulating online and shared on opposition social media sites purported to show the dead pilot surrounded by rebels from different factions.

Fadi Ahmed, a spokesman for the First Coastal Front rebel group, said "the Russian pilot was killed by gunfire as he fell with his parachute" in the Jabal Turkman area of Latakia province on the coast.

"The 10th Brigade (rebel group) transferred the body of the dead Russian to the local rebel joint operations room," added Omar Jablawi, a media activist working with rebels in the area.

He declined to specify exactly where the joint operations room was located.

The sources said rebels were still searching for the second Russian pilot of the Su-24 aircraft, which Ankara said was downed by Turkish forces after violating its territory.

The Syrian Observatory for Human Rights said Russian helicopters were combing the area between Jabal Turkman and government-held Kassab on the Turkish border searching for the second Russian.

Nearby, the monitor said rebels fired on a Russian helicopter, damaging it and forcing it to make an emergency landing in government-held territory.

The crew was able to flee but rebels blew up the helicopter shortly afterwards with a TOW anti-tank missile, the monitor said.

A video circulating online purported to show the helicopter on the ground being blown up.

US-made TOW missiles have been supplied by Washington and other rebel backers to several opposition groups in Syria.

Also online, opposition and rebel accounts on Twitter and Facebook circulated several videos depicting from several angles the man said to be the dead Russian pilot.

- Bloodied face -

In them, a man can been seen in military uniform with straps across his chest and blood on his face.

Rebels refer to the man as a "Russian pilot" and "Russian pig", but the location of the footage was not specified and it was impossible to verify the videos.

Russia began an air campaign in Syria on September 30, saying it was targeting the Islamic State jihadist group and other "terrorists".

But Syria's rebel groups and their backers accuse Moscow of focusing on Islamist and moderate opposition fighters rather than jihadists.

Fierce battles have raged for the past several days between rebel groups, not including IS, and regime forces backed by Russian air power in parts of northern Latakia province.

The regime has made some advances, though the frontline has shifted in both directions, according to the Observatory.

Putin warns Turkey after Russian jet downed
Moscow (AFP) Nov 24, 2015 - President Vladimir Putin warned Ankara on Tuesday that Turkey's downing of a Russian warplane on the Syrian border would have "serious consequences" for ties.

Speaking at a meeting with Jordanian King Abdullah II in the Black Sea resort of Sochi, a tense-looking Putin branded the shooting down of the aircraft a "stab in the back committed by accomplices of terrorists".

"I cannot call what happened today anything else," he said, accusing Turkey's armed forces of essentially backing up the Islamic State group.

"Today's tragic event will have serious consequences for Russian-Turkish relations," Putin said. "We will of course carefully analyse everything that happened."

Russia later announced that a planned visit to Turkey Wednesday by Foreign Minister Sergei Lavrov had been cancelled.

The fighter jet was shot down on the Syrian border by two Turkish F-16s, with Ankara saying the plane had violated Turkish airspace 10 times within a five-minute period.

Moscow said the fate of the two pilots was still unclear, while the Syrian opposition said one was dead and the other missing.

Putin rejected the accusations that the plane running sorties in Syria had violated Turkish airspace, saying it did not pose any threat to Turkey.

"Our plane was shot down over the territory of Syria by an air-to-air missile from a Turkish F-16 jet. It fell in Syrian territory four kilometres from the border with Turkey," Putin said.

"Our pilots and our plane did not in any way threaten Turkey, that's an obvious thing."

He said the plane was shot down as it was targeting members of the IS group in the northern Latakia region, adding that they mostly hailed from Russia.

"They were carrying out their immediate task of conducting preventative strikes against terrorists who could return to Russia any second."

Putin said NATO-member Turkey, which is part of a US-led coalition bombing the Islamic State group, shot down the plane despite Moscow's agreement with the United States to avoid such incidents.

"We will never tolerate such crimes," Putin said.

- 'Who needed that?'-

The Russian strongman also took issue with the fact that Turkey called a NATO meeting instead of reaching out to Moscow.

"It is as if we shot down a Turkish plane and not they ours," he said.

"We always treated Turkey not only as a close neighbour but a friendly state. I don't know who needed what was done today. Not us at least."

He accused Turkish armed forces of providing backup to the IS jihadists.

"What, do they want to place NATO at the service of ISIL?" Putin said, referring to the IS group by another acronym.

The defence ministry in Moscow summoned the Turkish military attache over the incident, while Ankara summoned the Russian charge d'affaires to the foreign ministry.

Jordanian King Abdullah II for his part expressed condolences at the loss of a Russian pilot and said the only way to end the conflict in Syria was through "your active participation, Russia's participation".