Five Special Ops soldiers were killed Monday in a possible friendly fire incident in Afghanistan.
Early reports indicate that the Americans called in for air support, and were mistakenly killed in an air strike.
Zabul Provincial Police Chief Gen. Ghulam Sakhi Rooghlawanay said that the incident occurred in the Arghandab district after the troops were attacked by the Taliban.
"After the operation was over on the way back, the joint forces came under the attack of insurgents, then foreign forces called for an air support," he told Fox News.
"Unfortunately five NATO soldiers and one Afghan army officer were killed mistakenly by NATO air strike,"
NATO's International Security Assistance Force confirmed the deaths, but would not confirm a friendly fire incident.
"The casualties occurred during a security operation when their unit came into contact with enemy forces," a statement released Tuesday read.
"Tragically, there is the possibility that fratricide may have been involved. The incident is under investigation. Our thoughts are with the families of those killed during this difficult time."
A senior defense official told Fox News that a B-1 bomber carried out the attacks.
Taliban spokesman Qari Yousef Ahmadi said that the terrorist group is responsible for the deaths, stating that a large number of NATO soldiers were killed or injured at their hands. More violence is expected this weekend as the Afghan presidential election is Saturday.
If confirmed, the incident is the highest number of American soldiers killed by friendly fire at one time during the War on Terror. In the Tarnak Farm incident in April 2002, four Canadian soldiers were killed by an American pilot when he dropped a bomb on them while they were conducting a firing exercise at night.
All American combat soldiers are expected to be withdrawn from the war-torn country by the end of the year. Monday's deaths bring the number of soldiers killed in 2014 to 36. Eight soldiers have been killed in June.