WASHINGTON, Sept. 4 (Xinhua) -- The U.S. Department of Defense on Tuesday identified the killed soldier who was supporting Operation Freedom's Sentinel in Afghanistan.

The Pentagon said that that "Command Sgt. Maj. Timothy A. Bolyard, 42, from Thornton, West Virginia, died Sept. 3, 2018, of wounds sustained from small arms fire in Logar Province, Afghanistan."

"The incident is under investigation," it added.

The U.S. forces in the Asian country said on Monday in a statement that an American soldier was killed and another wounded earlier on the same day in an "apparent insider attack" in eastern Afghanistan.

The soldier is the sixth American killed in the country this year, according to the statement.