The U.S. military is investigating a video posted to YouTube that appears to depict a U.S. service member opening fire on a civilian driving a truck in Afghanistan, U.S. military officials said.

The video, apparently recorded on a camera attached to a service member's helmet, shows a service member holding a shotgun as the truck rolls by his military vehicle. The passenger-side window of the truck shatters, though it is not clear that a round from the shotgun was fired.

The clip, first reported by Politico on Wednesday night, has prompted an investigation by U.S. Central Command, which oversees military operations across the Middle East and parts of southern Asia. Defense Secretary Jim Mattis is aware of the case, said Dana White, a spokeswoman for the secretary.

"We actually have very good procedures for this, as you know," Marine Lt. Gen. Kenneth F. McKenzie Jr., the director of the Pentagon's Joint Staff, told reporters on Thursday. "We take these allegations very seriously. … This is not something we look at lightly, and it'll receive all the serious attention that it deserves."

Politico reported that the video was initially posted anonymously under the title "Happy Few Ordnance Symphony," and quickly removed. It could mark yet another in a long line of instances in which U.S. troops have photographed or recorded video of themselves or their colleagues misbehaving in war zones, only to face criminal or administrative discipline afterward.

The video shows the service member carrying the shotgun wearing a pattern of camouflage often associated with Special Operations troops, though it isn't clear whether any were involved in the incident. It also isn't clear whether the shotgun was loaded with lethal ammunition, or a non-lethal alternative such as a beanbag, which U.S. troops sometimes carry.

Service members regularly shoot videos and photos, and YouTube is home to many videos recorded in combat. The U.S. military prohibits service members from taking photographs or video with detainees or human remains.