BEIRUT (Reuters) - Air strikes pounded a town in the eastern Syrian province of Deir al-Zor on Thursday, killing seven civilians and injuring more than 70 others, 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 Islamic State 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.

Islamic State 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.

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

Islamic State fighters launched their biggest attack in months on the government-held part of the city earlier in January, in a battle that killed dozens.

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