Syrian activist groups say Syrian warplanes have conducted a series of airstrikes on the northeastern city of Raqqa held by the extremist Islamic State group, killing at least 60 people.

The Britain-based Syrian Observatory for Human Rights said some of the air raids struck a popular market near a museum and an industrial neighborhood in the city of Raqqa along the Euphrates River in northeastern Syria.

It put the death toll at more than 60, among them 36 civilians. The Local Coordination Committees said the strikes killed at least 70 people. Another Raqqa-based collective said it documented over 80 deaths. Such discrepancies are routine in the immediate aftermath of attacks in Syria.

The Syrian government as well as the U.S.-led coalition frequently bomb Islamic State group targets in Raqqa.