Two Russian pilots have been killed in Syria after fighters from the Islamic State of Iraq and Levant (ISIL, also known as ISIS) shot down their helicopter near Palmyra, Russia's defence ministry has said according to local media.
The two men had been attacking a group of ISIL fighters in the Homs region on Friday, when the military chopper they were in ran out of ammunition, the Interfax news agency said, quoting the defence ministry.
"The turning helicopter was hit by militants' gunfire from the ground and crashed in the area controlled by the Syrian government army. The crew died," Interfax said.
ISIL claimed responsibility for the attack, according to SITE monitoring group.
Footage published on Saturday by ISIL's affiliated news agency Amaq showed a helicopter being shot and crashing to the ground.
Russian forces entered the Syrian conflict in late September last year, backing the forces of President Bashar al-Assad. At least 12 Russian soldiers have been killed since Moscow launched its military operation.
OPINION: Are the US and Russia helping or deceiving the Syrians?
In November, Turkish fighter planes shot down a Russian bomber on the Syrian-Turkish border, triggering a crisis in relations between the two countries.
Russia is helping Assad forces against ISIL and other rebel groups, mainly supporting the Syrian army with air strikes.
Western countries have accused Russia of also targeting Syria's moderate opposition and civilians - a claim denied by Moscow.