The U.S. military said Thursday that it is investigating a video posted on the internet showing what appears to be a U.S. service member shooting at a civilian truck while driving in Afghanistan.

A U.S. official said the weapons and equipment in the YouTube video suggest it could involve U.S. special operations forces and was likely taken last March. The official spoke anonymously to discuss details of the ongoing investigation.

In a blunt reaction, Army Gen. Joseph Votel, head of U.S. Central Command, said he reviewed the video, adding, "I am disappointed and also concerned that the American people, our Coalition partners, the Afghan government and the Afghan people will believe that American service members are callous and indifferent to the horrors of war or the suffering of innocent people trapped in conflict."

Votel said he rejects the "unprofessional and callous message this video conveys."

The video shows someone firing a shotgun at the door of a truck as they pass it on a snowbank-lined road. The driver of the truck can be seen as his window appears to be shattered by the shot. It's not clear if the driver or anyone else was injured. The video was first reported by Politico.

Officials said they are still trying to determine the details of the shooting and other portions of the video that depict the use of military-style weapons.

Central Command spokesman Col. John Thomas said the video "gives us serious concern." He said officials will take appropriate action.