Four U.S. military advisers were wounded in Syria earlier this month, CNN reported Monday.
The June 9 attack occurred when an anti-tank round blew up a vehicle situated close to the troops, defense officials said, and the attackers are believed to be connected to ISIS. The Pentagon has not yet publicly addressed the incident.
Recent Stories in National Security
The advisers returned to duty after recovering from light shrapnel injuries.
While defense officials suspect ISIS is responsible for the attack, they are uncertain of the assailants’ identity.
The Obama administration has maintained that ground troops are in Syria solely to advise, train, and assist local forces to further drive the militant group out of the region. Official policy states that the troops do not engage in combat roles.
Agence France-Presse published photos last month purporting to show U.S. special operations forces on Syria’s frontlines. The troops were seen climbing onto a rooftop "carrying U.S.-made anti-tank missiles," according to the report.
The Pentagon denied that the forces were on a combat mission.
American troops have been wounded or killed in Iraq or Syria at least five other times after coming under enemy fire while "training and assisting" forces supported by the United States, according to CNN.
Defense officials said they do not know the number of times U.S. forces have fired weapons against attackers because some incidents do not reach the level of importance requiring that they be reported to the Pentagon.