Man critical after Perth nightclub assault

A 21-year-old man is in a critical condition in hospital after he was assaulted during a fight that began in a Perth nightclub.

Police were called to the Lost Society Nightclub on Hay Street just after 2am on Sunday after reports that a female patron had been assaulted and about 15 men were fighting in the upper bar area.

Security staff intervened and moved the group outside onto the footpath area, where the scuffle continued.

A 30-year-old male security officer suffered cuts from being hit on the arm with a glass bottle while the 21-year-old man was punched and knocked unconscious.

He was taken by ambulance to Royal Perth Hospital and is in a critical condition.

Anyone with information about the incident is urged to contact police.