Two Syrian regime forces were killed in separate attacks by rebel groups in northern Idlib province.
Al-Fateh al-Mubeen's operation room said its fighters had killed an army officer and one soldier in separate attacks in Kafranbel town and near the M4 highway.
In its turn, the Russia jets have intensified airstrikes on Daesh pockets in Badia desert that stretches across central Syria to the eastern border with Iraq.
More than 220,000 regime forces have been killed since the armed conflict erupted nine years ago.
The conflict in Syria has also killed more than 500,000 people and displaced 13.2 millions.