A man, thought to be a member of US partner forces in Syria, sits on top of a detainee. Screenshot/Anadolu News Agency

A video recently surfaced showing US-backed forces torturing captives near the Syrian city of Raqqa, ISIS' de facto capital that was recently invaded by coalition forces.

The video shows men in YPG uniforms kicking and stomping prisoners. One YPG fighter holds a knife as he repeatedly bounces up and down on a stool on the back of one detainee. He then smashes an object over his head.

"Tell me where are the [ISIS] fighters," one YPG soldier says in Arabic, according to The Daily Beast. "Tell me."

"I swear I don't know," the detainee answered. "If you kill me, I will not be able to tell you because I don't know."

The Daily Beast said that the video was shot west of Raqqa in late May, citing Turkish media. Turkey sees the Kurdish-led YPG as a terrorist group and extension of the PKK, which has waged an insurgency against Ankara for decades.

Kurdish authorities in northern Syria have confirmed the incident, according to The Daily Beast.

Men in YPG uniforms standing over detainees. Screenshot/Anadolu News Agency

The Kurdish governmental body, or self-administration, in the Cizere Canton denounced the incident, saying it would prosecute the two YPG fighters, according to ARA News.

“Since they have broken laws and international criteria, they will be held accountable for their irresponsible, individual acts," the self-administration said.

Operation Inherent Resolve didn't immediately respond to request for comment.

Inherent Resolve spokesman Col. Ryan Dillon told The Daily Beast that, "the Coalition does not condone any violation of the laws of armed conflict and works hard in training to ensure partnered forces are aware of and understand the requirements of a professional fighting force to abide with these laws."

Numerous reports also began emerging in late 2016 that US-backed forces in Mosul were executing ISIS fighters and mutilating their dead bodies.