MOSCOW (National Times) — A fire in a cafe in the Russian city of Kostroma killed at least 13 people and injured five others on Saturday, local authorities said.

The governor of the Kostroma region, Sergei Sitnikov, said 13 people died in the fire and five more were slightly injured. Russian news agency Interfax cited local emergency officials as saying that the death toll stood at 15. The contradicting numbers couldn’t be immediately reconciled.

The blaze erupted in the early hours after someone apparently used a flare gun, according to the authorities. The Russian state news agency RIA Novosti reported that a brawl erupted in the cafe shortly before the fire, but it wasn’t immediately clear if it had anything to do with the use of a flare gun.

Rescuers were able to evacuate 250 people. The roof of the cafe collapsed during the fire, which engulfed an area of 3,500 square meters (more than 37,000 square feet). Firefighters spent five hours battling the blaze, and a dozen residents of a nearby residential buildings were evacuated as a precaution.

A criminal investigation has been launched, and the police have arrested a suspect.

Ikhtiyar Mirzoyev, a member of the regional legislature and owner of the cafe, promised assistance to those affected by the fire.

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.