MOSCOW (AP) — A fire in a cafe in the Russian city of Kostroma killed 15 people on Saturday, emergency 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. Kostroma is located roughly 340 kilometers (210 miles) north of Moscow.

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.