Police officer kicked unconscious in violent assault in Perth CBD on William Road

A police officer was allegedly the victim of a violent attack in Perth CBD that left him unconscious and with facial injuries.

A 16-year-old boy from Perth was arrested over the alleged incident. He was due to appear in court today.

WA police say the 36-year-old officer was off duty when he was allegedly approached by the teen at Perth train station around 11:15 p.m.

The man was an off duty cop. (AAP)

Police said there was an altercation before traffic officials helped the man and put an end to the confrontation.

The teenager allegedly approached the man a second time, kicked him in the head and knocked him unconscious outside a fast food place on William Street.

The man suffered a broken eye socket and nose. He was taken to the Royal Perth Hospital for treatment for his injuries.

The teenager was later arrested at an address in Kingsley.

He was charged with intent to inflict serious assault on another.

Anyone who has information about the incident, has seen it, or may have footage of it, is encouraged to call Crime Stoppers on 1800 333 000 or report the information online at www.crimestopperswa.com.au.