masked tugs storm club Russia video Vichuga Streletz
Security camera footage shows masked tugs storming a club in Russia.YouTube

A video showing a Russia man calmly sipping a drink as dozens of masked thugs storm a nightclub, sparking a mass brawl has gone viral.

Up to 35 men wearing balaclavas are seen in security camera footage as they enter the Streletz (Saggittarius) club in the central town of Vichuga, 400 km northeast of Moscow, and make a beeline for a group of customers - four men and a woman - sitting at a table.

A punch-up ensues as terrorised customers witness the unfolding violence and attempt to flee. All but one, actually. A young man in fact remains seated despite being quickly abandoned by his tablemate. As the bandits wreak havoc all around him, he finishes his drink, looking unimpressed.

The affray lasts for about 60-seconds, after which the thugs are seen running out of the building.

Police said they were called at the scene by Streletz staff but the assailants had already fled when they arrived "due to the brevity of the incident".

Four people were wounded in the incident that occurred early Sunday morning and is being investigated, authorities said. Motives were not immediately clear.

In another, longer video of the brawl, the attackers are seen as they arrive and leave from the club.

Some are seen wielding iron bars and batons, while one of the last to enter the premises appears to be holding a rifle.

They all sport white armbands, an identification device often used by Russian security forces when operating plain-clothed.

Similar armbands were infamously used by the so-called green men, alleged Russian troops wearing no insignia that backed separatist militias in Crimea, southern Ukraine, earlier this year.

The detail prompted some internet commentator to speculate that the attackers were members of riot police. The claim is unconfirmed.