Syria's state news agency is reporting that troops have regained control of areas they lost to the Islamic State group in the east of the country after an airstrike by the U.S.-led coalition.

SANA quotes an unnamed military official as saying Sunday that dozens of IS fighters were killed in the offensive under the cover of Syrian airstrikes.

The Syrian military official said government troops had regained control of areas the extremists captured, "as a result of the American aircraft aggression."

The U.S. military said it may have unintentionally struck Syrian troops while carrying out a raid against IS on Saturday.

Russia's military said it was told by the Syrian army that at least 62 soldiers were killed in the Deir el-Zour air raid and more than 100 wounded.