RAQQA — Airstrikes pounded northern Raqqa and the eastern province of Deir al-Zor on Thursday, killing 23 and seven civilians, and injuring more than 80 others in both cities, the Syrian Observatory for Human Rights said.

The Britain-based war monitoring group said two warplanes, believed to be Russian, dropped nearly two dozen bombs on al-Mayadin in the ISIS stronghold of Deir al-Zor. The strikes hit a school sheltering displaced people, a bakery and residential areas in the town, which lies along the Euphrates river, the Observatory said.

The Syrian government and its Russian ally have repeatedly said they only target militants. ISIS controls most of Deir al-Zor province, which borders Iraq, including more than half the city of the same name. The ultra-hardline jihadist group has besieged the remaining government-held areas of Deir al-Zor city for nearly two years.

In Raqqa, warplanes were believed to belong to the U.S.-led coalition against the ISIS militants, the Observatory said.

Jets also hit the southern outskirts of the city on Thursday, the Observatory said.

The Syrian and Russian air forces hit back against ISIS positions, and have regularly struck the city and surrounding rural areas since then, the Observatory said.