Updated

The U.S. military is investigating a shooting in Afghanistan based on a video posted to the Internet showing what appears to be a U.S. service member firing his weapon into a civilian truck.

It’s unclear from the footage if any Afghan civilians were hurt in the shooting, which was first reported by Politico.

Defense Secretary Jim Mattis has been briefed about the investigation, Fox News has been told.

The video compilation appears to show U.S. special operations forces engaged in combat. The portion of the video drawing scrutiny takes place about 20 seconds into the 3-minute clip.

In a statement provided to Fox News, the head of U.S. forces in the Middle East and Afghanistan condemned the video, saying it sends a  “callous message” to the world.

"I have reviewed the video and 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," said Gen. Joseph Votel, commander of U.S. Central Command.

"I can assure you that this video does not represent the professionalism or humanity of the men and women of U.S. Central Command. We reject the unprofessional and callous message this video conveys."