The U.S. military said late Wednesday that civilians “were likely killed” during a Navy SEAL raid in Yemen on Saturday, a ground operation that erupted into a massive firefight that also took the life of an American sailor.

A statement issued by the U.S. Central Command said that an investigatory team “has concluded regrettably” that an unspecified number of civilians “appear to have been potentially caught up in aerial gunfire that was called in to assist U.S. forces” that were “receiving fire from all sides.”

Media reports from the region said that at least 10 Yemeni women and children were killed in the raid, the first counterterrorism operation authorized by President Trump.

The speed with which the military acknowledged the civilian deaths was in stark contrast to the investigations after most previous allegations of civilian casualties, which have often taken months, if not years.

The goal of the operation was to detain Yemeni tribal leaders allegedly collaborating with al-Qaeda in Yemen and to gather intelligence about the group. Instead, a massive firefight ensued that brought in U.S. aircraft to strike the fighters and rescue the military team.