Col. Gen. Sergei Rudskoi of the Russian militarys General Staff said Friday that Russian fighter jets have carried out 90,000 airstrikes since Moscows direct military intervention in Syria in September 2015, allowing the Syrian regime to quadruple the territory under its control. At a news conference in Moscow, he said the area under Syrian regime control has increased from 19,000 to 78,000 square kilometers. Russian pilots have flown more than 28,000 missions since the campaigns launch, he told reporters. Rudskoi said Syrian regime troops are advancing from three directions to encircle Deir el-Zour. "Breaking the blockade of the city will mark the defeat of the most capable part of the ISIS in Syria," he added. Meanwhile, ISIS militants pushed back regime forces advancing on one of the last towns still in the terrorist group’s hands in the province of Raqqa, killing 34 soldiers and seizing vehicles, a Syria monitoring group said. The Britain-based Syrian Observatory for Human Rights said the early Friday counterattack by ISIS short-circuited a regime advance on Maadan, which brought them within only a few kilometers in recent days. ISIS’ Amaq propaganda agency said 57 Syrian troops were killed in the attack. The Russia-backed regime forces have been on a multi-pronged offensive, moving toward the ISIS-held territories in Deir el-Zour province in the east from northern, central and southern Syria. On Friday, the Russian military said its air force is now focusing on supporting the Syrian forces offensive in Deir el-Zour. Syrian regime forces control around half the city and a nearby air base, both of which are besieged by the ISIS militants.