At least 13 people died in an overnight fire at a nightclub in the Russian city of Kostroma, officials said on Saturday.
Kostroma is a city of around 270,000 people, 300 km (190 miles) north-east of Moscow on the banks of the river Volga.
The fire took place at Polygon, a multi-purpose recreation venue used as a cafe, nightclub and bar.
"As a result of the fire, 13 people died; the number of dead and injured is being clarified," the judicial Investigating Committee said in a statement.
The fire was extinguished as of 7:29 a.m. (0429 GMT), according to the regional governor, who put the number of injured at five.
Video shared by investigators showed firefighters spraying water on what appeared to be the smouldering, collapsed roof of the building.
TASS news agency cited investigators as saying the fire may have started after a man fired a flare gun indoors.
Investigators said they had launched criminal proceedings.