Six long-range bombers from Russia on Sunday destroyed Islamic State group weapon stores around the militant stronghold of Deir Ezzor in eastern Syria, the defence ministry in Moscow said.
The ministry said in a statement that the Russian Tupolev bombers carried out raids to the southwest, east and northeast of the city, wiping out two command posts, six arms depots, IS group vehicles and "a large number of fighters".
IS group controls large parts of Deir Ezzor city and most of oil-rich Deir Ezzor province in the east of the country, and has battled Syrian regime forces for control of a key military airbase there.
Russia has been flying a bombing campaign in support of long-time ally President Bashar Al-Assad since September that has helped shore up the strongman's crumbling forces.
IS group militants were on Friday forced out of the city of Manbij near the Turkish border by a US-backed Arab-Kurdish alliance in a blow the Pentagon said showed the extremists were "on the ropes".
Russian-backed government forces are also battling other rebels groups in fierce fighting for the country's second city of Aleppo, a fortnight on from the launch of a major rebel offensive.