The air raids hit ISIL fighting positions and tactical units in the city of al-Bukamal and the Susa town in Deir Ezzur, ARA News reported.
“At least 31 ISIL militants were killed in the airstrikes launched by Russian Air Force,” local media activist Samer al-Khalaf said.
A source close to ISIL also confirmed the death of dozens of the group’s fighters in the raids.
“The national hospital in Deir Ezzur City received more than 30 corpses of ISIL members subsequent to the airstrikes,” a doctor in the national hospital told ARA News, speaking on condition of anonymity.
Also, four civilians were reported dead in the bombardment of Deir Ezzur on Sunday.
In the meantime, clashes broke out between Syrian army forces and ISIL fighters in the districts of Joura and al-Rashidiya in Deir Ezzur City.
“The Syrian regime’s army forces tried to exploit the Russian strikes to advance on the ground and secure the two neighborhoods from ISIL militants,” al-Khalaf reported.
The clashes continued until Monday morning. It was not immediately clear whether the Syrian army made any new gains.