Syrian and Russian warplanes carried out an air raid on a market in the eastern province of Deir al-Zor on Monday killing at least 17 people, Syrian Observatory for Human Rights monitoring group reported.

The strikes hit the town of Ashara, about 60 km (40 miles) southeast of the provincial capital, Deir al-Zor city. Eight children were among those killed and the toll was expected to rise because of the high number of serious injuries, the Britain-based Observatory said.

Warplanes bombed other areas of Deir al-Zor province, which is mostly under the control of ISIS terrorist group. The group has laid siege since March last year to the remaining government-held areas in Deir al-Zor city.

Assad forces launched an offensive against ISIS last week starting from Hama province further west, pressing towards the jihadists’ stronghold in Raqqa province, which borders Deir al-Zor.

Deir al-Zor province links Raqqa with Iraq, where the group also controls territory.

A Syrian military source said the army had captured a crossroads in its latest offensive from which it could advance towards Raqqa, Deir al-Zor or eastern Aleppo.