Victoria police Chief Jamie Graham, a fomer chief in Vancouver, says an incident caught on a video posted on YouTube, showing a uniformed officer repeatedly kicking and kneeing two suspects, will be investigated by Vancouver police. (CBC)

A Victoria police officer seen on a YouTube video kicking two men who already appear to be under control is now facing an external police probe.

Officers from the Vancouver Police Department will conduct the investigation, Victoria police Chief Jamie Graham said Wednesday.

The officer, who's now on desk duty, was a supervisor when police were called to a reported brawl outside a Victoria nightclub Sunday night that resulted in six arrests but no charges.

The Victoria department's professional standards section launched an internal investigation Tuesday after the video surfaced on the popular video-sharing website.

Graham did not say if the internal investigation would continue now that the Vancouver department had become involved.

Police have said they were breaking up a brawl involving eight men early Sunday morning outside the Social Club on Store Street when part of the incident was caught on camera.

The amateur video shows police struggling to arrest several men, when an officer appears to kick one man several times as he is held on the ground.

The same officer then turns and yells at a second man, kicks him and knees him as another officer holds the man down.

Police said the officers used pepper spray in an effort to disperse those involved and took six people into custody. A man found lying on the ground was taken to hospital with a head injury and was treated and released, police said.

None of the officers was injured.

Knee strikes raise concerns

David Eby, executive director of the B.C. Civil Liberties Association, said the video is troubling for several reasons, particularly the knee strikes by the officer against the man's back, the kind of blow that can break ribs.

A man hidden in this photo by a rock in the foreground is held down by one officer while another kicks him in the ribs. (YouTube)

"The Vancouver Police Board has actually issued specific directions to its members about knee strikes, saying there is a danger of breaking someone's ribs when you direct it to someone's torso, and that the ideal area for a knee strike is actually the upper thigh, not someone's torso," said Eby.

Victoria Mayor Dean Fortin wouldn't comment on the incident Tuesday, saying it was under investigation, but he did say the city has been struggling with drunken, disorderly behaviour and has beefed up its police presence in the downtown core.