At least 32 Islamic State fighters were killed and 40 more wounded in Syria's Raqqa province on Sunday, in a series of air strikes believed to be carried out by a U.S.-led coalition targeting the Militants, a monitoring group said.

More than 15 explosions hit ISIS positions in the countryside of Raqqa province and near its capital, Raqqa city, the Britain-based Syrian Observatory for Human Rights said. Raqqa is Islamic State's Syrian stronghold.