10/10/2014 04:24 EDT | Updated 10/10/2014 04:59 EDT

RCMP Video Of Violent Arrest In B.C. Investigated (GRAPHIC)

The B.C. police watchdog is investigating a video that appears to show an RCMP officer repeatedly punching a handcuffed teen in the head.

The video, obtained by the Terrace Standard newspaper and posted to its YouTube account on Thursday, shows the unidentified officer hitting the young man, who is handcuffed and lying face down on the ground.

The May 28 incident in the northwestern B.C. city was captured on a cellphone. The Terrace paper, which received the video on Sept. 25, says it does not know who filmed it.

Officers were responding to a call about a fight between a female and male, Insp. Dana Hart, the Terrace RCMP commanding officer, told the Standard. They were both taken into custody but the male, who is under 18, cannot be named under the Youth Criminal Justice Act.

Terrace RCMP forwarded the video to the Independent Investigations Office (IIO), which probes incidents involving B.C. police that lead to death or injury. The agency is now investigating the incident.

There's no way to predict how long the investigation will take, the IIO's Owen Court told The Vancouver Sun.

A second probe — an RCMP code of conduct review — is also underway, reported CBC News.

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