The Islamic State (ISIS) group has claimed the killing of five Russian troops in fighting near the ancient Syrian city of Palmyra.
"The soldiers of the caliphate, by the grace of God, have killed five Russian soldiers and six members" of the Syrian army, ISIS said in a statement.
The group also claimed the killing of several members of the Lebanese Iran-proxy Hezbollah terror group in fighting near Palmyra.
A website linked to ISIS, Aamaq, carried a similar claim, adding that one of the Russians killed was a military adviser.
"Four of the Russian soldiers were killed in Qasr al-Halabat west of Palmyra during an attempt to storm the area that ISIS forces foiled, while the adviser whose corpse was shown in a video distributed by the agency died (Thursday) in the Dawa area," Aamaq claimed.
Aamaq also published a video, showing the bloodied corpse of a man in military gear that it claimed was the adviser.
The footage also shows equipment presumably captured, including a customized AK-74M rifle, a helmet and a compass. A packet of bandages was filmed with instructions written in Russian.
ISIS seized Palmyra, a UNESCO World Heritage Site in eastern Syria known as the "Pearl of the Desert," last May, sending shock waves across the world.
The Syrian Observatory for Human Rights monitor said that Russian advisers were present near Palmyra, but could not confirm whether any Russian forces had been killed there in recent days.
President Vladimir Putin, Assad's main backer, on Monday ordered the withdrawal of most of Russia's armed forces from Syria.
The Russian air force has however continued to strike jihadist targets since the surprise announcement, particularly around Palmyra.
Russia's defense ministry did not reply to an AFP request for information on the jihadist claim.
"Our uncompromising attitude to terrorism remains unchanged," Putin said Thursday, adding that "fierce fighting" was raging near Palmyra.
He also named four Russians killed in action in Syria since Moscow launched a military intervention in Syria on September 30, including a military adviser.
Previously, the defense ministry's official toll had been three, excluding a soldier who committed suicide.
AFP contributed to this report.