Police officer knocked unconscious in shocking Facebook Live video

Three men have been charged with assaulting a police officer over a bashing that left a male constable unconscious in Cairns.

A local man broadcast video to Facebook Live as the alleged assault took place on the city's popular Esplanade about 7pm yesterday.

Police allege the 28-year-old officer was surrounded by a group of men he had approached after a disturbance at a nearby venue.

He was then allegedly assaulted and fell to the ground, but the men continued their attack and knocked him unconscious, police allege.

The officer's partner then used capsicum spray and the men fled, only to be arrested a short time later on Abbott Street.

The injured officer was taken to Cairns Base Hospital suffering multiple cuts.

He was in a stable condition and will undergo scans today, police said.

A 20-year-old Edge Hill man has been charged with serious assault police, serious assault police causing bodily harm, two counts of assault police and wilful damage of police property.

Two Brinsmead men, aged 21 and 22, have each been charged with serious assault police causing bodily harm and wilful damage of police property.

All three men are expected to appear in Cairns Magistrate today.