A fire in a cafe in the Russian city of Kostroma killed 15 people and injured five others on Saturday, local authorities said.
The blaze erupted in the early hours after someone apparently used a flare gun during a dispute, authorities said.
Rescuers were able to evacuate 250 people. The governor of the Kostroma region, Sergei Sitnikov, said five people were slightly injured and received medical assistance.
The roof of the cafe collapsed during the fire.
A criminal investigation has been launched, and the police are searching for the person who used the flare gun.
Kostroma, a riverside city of 270,000, is located roughly 340 kilometers (210 miles) north of Moscow.
It wasn't the first time that pyrotechnics caused a deadly fire at a recreational venue in Russia. In 2009, more than 150 people were killed in a blaze at the Lame Horse nightclub in the city of Perm that erupted after someone set off fireworks.