At a Pentagon briefing Thursday, officials said Defense Secretary Jim Mattis and Joint Chiefs Chairman Gen. Joseph Dunford had been briefed on what the video purports to show.
Concern about a video allegedly showing an American service member firing into the cab of a civilian truck in Afghanistan has reached the highest levels of the Pentagon.
One brief clip amid the footage shows an armored vehicle driving past a truck.
Central Command (CENTCOM) issued a statement insisting that the video was "not authorized" and that the shooting of the civilian vehicle was not in keeping with engagement policies for ground troops there.
"We are conducting an investigation into this video, and will take appropriate actions as a result of this investigation", Thomas added.
However, the short clip does not show what happened to the driver.
According to Politico, the video was posted on YouTube and was called "Happy Few Ordnance Symphony".
The brief video clip is reportedly part of a three minute, nine second video of US troops serving in Afghanistan firing various weapons.
The longer video was posted on a Facebook page and has since been deleted but has been reposted on other sites. The clip, apparently recorded on a helmet camera, shows a shotgun being pointed at the truck cabin and the window on the driver's side being shattered as if it had been shot. "We reject the unprofessional and callous message this video conveys".
He said: "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".
"This video does not represent the professionalism or humanity of the men and women of US Central Command".