A mass brawl involving 40 clubbers armed with champagne bottles, knives, and a “firearm” has led to a popular nightclub being temporarily shut.

Four people were taken to hospital with serious injuries when a “vicious” fight broke out in the NWC nightclub in Finchley Road, Swiss Cottage, during a promotional event for an upmarket vodka.

Reports from police, who ­received multiple 999 calls in the early hours of December 22, said the trouble began when a man was the victim of a “feral attack” by five other men armed with champagne bottles.

The assault, which left the victim “motionless”, was said to have “set a tone” for multiple further disturbances, with 40 people involved in fights on the dance floor. When one man entered the club concealing an object the dance floor was said to have descended “into panic” with people shouting that they had seen a gun.

Around 100 revellers spilled out and fights continued in the street. A police helicopter, 30 officers and three ambulances went to the scene.

A 26-year-old man and a 33-year-old woman had stab wounds to their leg and stomach while two others were said to have lacerations to their heads and faces.

A worker for the event, who did not wish to be identified, said: “It started off as a typical argument between five or six revellers that turned into a very untypical and very physical brawl. I watched as one guy was ambushed by five other men. He was unarmed and on the floor, and they were kicking him, punching him and using champagne bottles as weapons.

“You could just see him just lying there, bleeding.

“It could have been so much worse, thank God nobody lost their lives. I’ve seen a few fights in my time but this ranks as one of the worst.”

The club was trashed and the dance floor littered with broken glass .

The drain on resources was said to have been so extensive that special constables were left without the use of cars and had to travel to emergencies by bus.

Camden Council’s licensing committee suspended the club’s licence until a full hearing on January 23.

Owners of the nightclub, Elite Privee Ltd, could not be contacted for comment.

There have been no arrests.