Russian warplanes have carried out dozens of air strikes on the Islamic State (IS) group's positions in the Syrian Desert, activists say.
The jets are supporting an operation by Syrian pro-government forces to secure the road between Homs and Deir al-Zour, according to a monitoring group.
IS militants have carried out a string of deadly ambushes and hit-and-run attacks in the region recently.
The latest, on Wednesday, reportedly killed nine soldiers and militiamen.
The UK-based Syrian Observatory for Human Rights, which monitors the war in Syria via a network of sources, said three others had died on Tuesday when a landmine planted by IS exploded in the desert near al-Mayadeen, in south-eastern Deir al-Zour province.