Thaier Al-Sudani / Reuters
These were the first such reports of alleged abuse in a U.S.-backed campaign to retake the city from ISIS.
At least 1,601 civilians were killed and 3,565 wounded in the war in the first six months of 2016.
At least 56 civilians, including 11 children, died in airstrikes on Tuesday, monitors said.
At least 56 civilians were killed, including 11 children, a monitoring group says.
The total is far lower than estimates by non-governmental organizations.