DAMASCUS: Seven soldiers and pro-government fighters were killed during an Islamic State (IS) attack on military sites in Syria's Deir al-Zour province, a war monitor reported early Saturday.

According to Syrian Observatory for Human Rights, the attack was launched on military positions east of the T2 oil station in southern Deir al-Zour.

The UK-based watchdog placed the death toll of such attacks so far this year at 594, including 44 IS militants, 385 soldiers and pro-government fighters, as well as 165 civilians, Xinhua news agency reported.

The IS has lost key areas in Syria and its fighter cells have to resort to reposition and guerrilla warfare in the sprawling desert region of eastern Syria.