Firefighters at around 5:00 am (midnight GMT) pulled 10 people from the two-storey concrete building, but eight were pronounced dead at the scene, the regional branch of the emergency ministry said in a statement.

Up to 15 people could have been working a night shift, leading to fears that more people could have died, a spokesman for the ministry told the Interfax news agency.

Two survivors have been hospitalised with burns in Perm, the regional capital around 1,200 kilometres (700 miles) east of Moscow, the emergency ministry said.

Perm was the scene of one of the deadliest accidents in recent Russian history in December 2009, when a fire in a crowded nightclub killed 156 people who were unable to escape choking fumes through a single narrow exit.