Islamic State militants pushed back government forces advancing on one of the last towns still in IS hands in the province of Raqqa, killing over two dozen soldiers and seizing vehicles, a Syria monitoring group and the extremists said.
The Britain-based Syrian Observatory for Human Rights said the early Friday counterattack by IS short-circuited a government advance on Maadan, which brought them within only a few kilometers (miles) in recent days.
The Russia-backed government forces have been on a multi-pronged offensive, moving toward the IS-held territories in Deir el-Zour province in the east from northern, central and southern Syria. Maadan lies halfway between Raqqa city and Deir el-Zour city, which is divided between government and IS controlled areas.
With assistance from Iranian-organized militias, Syrian troops have also been able in recent months to recaptured large parts of the country from rebels and militants.
On Friday, the Russian military said its campaign backing the Syrian government since 2015 has allowed President Bashar Assad's forces to quadruple the territory under their control.
Col. Gen. Sergei Rudskoi of the military's General Staff said in a news conference in Moscow Friday that the area under Syrian government control has increased from 19,000 to 78,000 square kilometers (7,335 to 30,115 square miles) since Russia launched its air campaign in September 2015. Russian pilots have flown more than 28,000 missions since the campaign's launch, he said.
Rudskoi said the Russian air force is now focusing on supporting the Syrian army's offensive in Deir el-Zour. Syrian government forces control around half the city and a nearby air base, both of which are besieged by the IS militants.
The IS attack Friday set the government back about 30 kilometers (19 miles) to the west of Maadan. It also allowed the militants to recapture a number of villages in the areas they lost to advancing government troops last month. Maadan lies halfway between Raqqa city and Deir el-Zour city, which is divided between government and IS controlled areas.
The Observatory called it the biggest attack by IS in southeastern Raqqa. It said at least 34 Syrian soldiers and 12 militants were killed.
IS media channels posted pictures of the attacked Syrian army convoy and bodies of over a dozen soldiers.
The militants have unsuccessfully tried to push back against government advances in central Syria.
Maadan lies along the southern banks of the Euphrates River and is 60 kilometers, or 37 miles, east of the city of Raqqa, where the U.S-backed Syrian opposition forces are separately battling IS.