June 10 (UPI) -- Two U.S. soldiers were killed and one other was injured when an Afghan soldier opened fire on Saturday, the U.S. military said.
The shooting took place in the Achin district of Afghanistan's Nangahar province, where a security official said the gunman was killed by U.S. troops.
U.S. Special Operations forces had been working alongside Afghan commandos to conduct counter-Islamic State operations in the mountains of Achin.
"We are aware of an incident in Eastern Afghanistan. We will release more information when appropriate," Douglas High, a spokesman for Operation Resolute Support, told The Washington Post.
A spokesman for the Taliban, which is active in the area, said the group claimed responsibility for the attack and described the shooter as an "infiltrator" of the U.S. Army.
Two Afghan border policemen were also recently killed by U.S. aircraft friendly fire during a joint operation in the southern province of Helmand.
The U.S. military apologized for the deaths and senior international diplomat in Afghanistan said authorities are investigating the possibility the incident could be connected to the shooting by the Afghan soldier.