A Russian pilot was killed on Saturday after rebels shot his warplane down over Syria’s northwest province of Idlib, AFP quoted Russia’s defence ministry and a monitor as saying.

“The pilot was killed on the ground as he fought the Islamist rebels who shot down his plane and were taking him captive,” Syrian Observatory for Human Rights Chief Rami Abdel Rahman said, according to AFP.

The Britain-based monitor said the Sukhoi 25 was shot down over the town of Maasran in Idlib and the pilot came down in a parachute. Rahman said there was no information yet about which factions were involved.

However, reports in the Los Angeles Times and Reuters said Mahmoud Turkmani, a militant commander in the Organization for the Liberation of Syria, claimed responsibility for shooting down the plane.

According to Reuters, Turkmani belongs to the Tharir al-Sham, a jihadist group headed by a former Syrian branch of Al Qaeda. “This work is the least we can do to revenge our people,” Turkomani said in a statement released by the group. “Let the criminal invaders know that our skies are not a picnic and they will not pass through without paying a price God willing.”

The rebels oppose President Bashar al-Assad, whose troops are backed by Russia, as they see Russia as an invading force who they blame for the deaths of thousands of civilians.