(CNN)At least 32 ISIS militants were killed in airstrikes Sunday in Syria's Raqqa province, the UK-based Syrian Observatory for Human Rights reported.
The group, which is in opposition to the Syrian regime, also said 40 others were wounded.
There were more than 15 airstrikes on ISIS positions in the countryside of Raqqa province, the observatory said. It was not immediately clear if any of these strikes targeted the city of Raqqa, the self-declared capital of ISIS, which is also in Raqqa province.
It was unclear which country conducting bombing operations in Syria was responsible for the airstrikes against ISIS.
France, Russia and the United States have all carried out airstrikes in and around Raqqa in recent weeks.
The neighboring province of Deir Ezzor has also seen a sharp rise in the number of airstrikes targeting ISIS oil production, refining and transport. These attacks have included strikes against the Omar oilfield, one of the most productive in ISIS territory. Britain's Royal Air Force has bombed it within the past 48 hours.
