U.S. commanders investigating claims of civilian casualties in Syrian airstrike

American commanders in Syria said Wednesday they are investigating claims that over 33 Syrian civilians were killed in a coalition airstrike near the Islamic State-held city of Raqqa.

The airstrike, which was part of a larger offensive by the U.S.-backed Syrian Democratic Forces, or SDF, to recapture the critical Tabqa Dam area roughly 30 miles west of Raqqa.

Eyewitness reports claim the target struck in the Syrian town of Mansoura Tuesday was actually a converted schoolhouse used to harbor refugees fleeing nearby fighting. Coalition officials claim the target was a operational hub for fighters loyal to the Islamic State, or ISIS or ISIL.

American and coalition officials did not dispute that civilians could have been killed in during the airstrike in Mansoura, but they have yet to receive confirmation of those types of casualties, spokesman Col. Joseph Scrocca told reporters at the Pentagon Wednesday.

“We have seen this before,” he said regarding the group’s tactic of using civilians as human shields to protect its positions, or blowing up known civilian buildings and blaming the ensuing body counts on careless operations by U.S. and coalition forces.

However, images of the attack site circulating on social media clearly show the building had been struck with some type of air-launched weapon.

While acknowledging that only American aircraft were flying in the skies above Mansoura at the time of the strike, Col. Scrocca suggested the alleged civilian casualties could have been caused by ISIS itself.