A video posted to YouTube that may depict American Special Operations forces violating protocols in Afghanistan has triggered an investigation by the United States military.

One segment of the video shows a service member firing a weapon into the driver’s window of a civilian truck from a short distance. The window is shattered, but it is unclear if the driver is injured — or why the shot was fired.

Gen. Joseph L. Votel, head of United States Central Command, said the video, which consists of over 40 individual clips, is “not official, not authorized and does not represent the professionalism of the service members of U.S. Central Command.”

An Army Special Forces soldier who had direct knowledge of the incident said the shooter’s action did not violate protocols.

“Anyone who was there would say that it was within our rules of engagement, and the whole video gives context,” the soldier, who spoke on condition of anonymity, told The New York Times. “It was a vehicle in the American convoy, and we had standard operating procedure with a shotgun carried in our vehicle’s turret loaded with less than lethal rounds.” His statement could not be independently confirmed.

Here’s what we know about the video.

Who made the video public?

The three-minute video was uploaded to YouTube on Dec. 16 as part of a marketing campaign for a company called Happy Few, which was set up to sell military-themed apparel. The manager of Happy Few is assigned to a Special Forces unit, according to Army documents. Snippets of the video were also posted to Happy Few’s Instagram account.

Set to music by the American rap artist Kendrick Lamar, the video depicts United States soldiers firing a variety of weapons.

The video was recently removed from YouTube. Happy Few’s website and Instagram page were deleted soon after Central Command said on Wednesday that it is investigating.

The existence of the video was reported by Politico, which showed it to military officials and, in turn, led to the investigation being opened.

The gun

The weapon in the video appears to be a tactical shotgun made by Benelli, an Italian firm that supplies weapons to militaries and police forces around the world, including the United States military. It is a lightweight shotgun, sometimes carried by Special Forces and other ground troops. The shotgun is frequently used in close-quarters combat and for breaching doors in raids.

The soldier who spoke to The Times said the round that was fired was “less than lethal.” An apparent lack of recoil or a discharged cartridge suggests that the shotgun may have fired a bean bag or rubber bullet. These can be lethal when fired at close range.

Military protocols on situations of escalating force dictate how troops deal with an approaching vehicle that is seen as potentially hostile. The instructions typically call for shooting at tires, then the grill, then the driver. But these rules have changed over the years and it is unclear which protocols this unit was following — or even when the shooting took place.

Convoy operations such as those shown in the video sometimes employ different tactics to make sure civilian vehicles stay out of the way of American vehicles. This footage, however, provides little contextual information about why the soldier fired into the truck.

In the 16 years that United States troops have been in Afghanistan, cars and trucks carrying bombs have often rammed American convoys. Driving Afghan roads is a fraught experience for American troops, with countermeasures and self-defense options that are all imperfect and depend on human judgment.

The military vehicle

The RG33 SOCOM Cat II military vehicle is a variant of the kind carrying the service member as he fired his weapon. Image via BAE Systems.

Several features of the military vehicle suggest it is a variation of an RG33 MRAP Special Operations Vehicle, commonly used by U.S. forces in Afghanistan: the wheel mounted on the side of the vehicle, the winch above the wheel, the side-facing flood light to the rear, space for two upward hatches, the hitch to the front upper corner of the vehicle.

Is it Afghanistan?

The video was described on YouTube as “Special Operations Forces in Afghanistan in the most recent combat footage to date against ISIS in 2017.” The fight against the Islamic State in Afghanistan largely is taking place in Nangarhar Province, in the eastern part of the country.

And an American official familiar with the investigation into the video told The Times that the footage was likely filmed recently in eastern Afghanistan.