Russian police on Saturday detained a man suspected to have caused a huge fire overnight at a bar in the historic city of Kostroma that killed at least 15 people.

Fire fighters fought through the early hours to extinguish the blaze at the popular Poligon bar in the city, which is around 300 kilometres (180 miles) northeast of Moscow.

Russian agencies reported that the fire could have started after a drunk man fired a “flare gun” on the dance floor.

“Police officers identified and detained the suspect (behind) unlawful acts in an entertainment establishment in the city of Kostroma, which resulted in a fire and the death of people,” Russian police said.

“He has now been handed over to investigative authorities,” it added, without providing any further details.

Russia’s Investigative Committee opened a criminal case of “causing death by negligence”.

It published images from inside the burnt-out building, showing a barely recognisable bar with some visible stickers of beer brands. The bar had a collapsed roof and burnt-out walls, with near total destruction inside.

State television aired night-time images of the bar — housed in a single-storey logistical centre — engulfed in flames.

Authorities said the fire started at around 2:00 am local time (2300 GMT Saturday) and was put out at around 7:30 am.

Kostroma regional governor Sergei Sitnikov said 13 people were killed.

– ‘Flare gun’ –

“Two more bodies were recovered. This means the number of victims is now 15,” the TASS news agency later quoted law enforcement sources as saying.

Around 250 people were evacuated from the building when it caught fire, authorities said earlier.

TASS, citing emergency service sources, said a drunk man with a “flare gun” was likely to have caused the fire.

“He was spending time in the bar with a woman, ordered her flowers, with a flare gun in his hands,” the source told the agency.

“Then he went to the dance floor and fired it.”

Emergency services said the blaze engulfed more than 3,500 square meters (37,700 square feet).

Some local media, quoting witnesses, said here was panic when the fire started as people rushed to an exit, causing a jam. One man forced a closed door open, possibly saving lives, according to reports.

The RIA Novosti news agency said the bar belonged to a local deputy of the ruling United Russia party, Ikhtiyar Mirzoyev.

He told the agency that he would “give all the necessary help to the families and loved ones of the dead.”

On its website, Poligon says it acts as an evening and night-time “place for recreation and entertainment”.

– Lax safety –

By day, it is a typical Russian “stolovaya” — a casual restaurant serving traditional food.

It says it is housed in a “distribution centre” and is popular with traffic police.

State television showed images of dozens of emergency workers fighting the inferno.

The sign “Poligon” was visible amid the flames raging on its roof.

One fire fighter told state television that it took 50 people to extinguish the blaze and that they had used 20 fire engines.

He said the fire was especially difficult to put out because of a risk that the building might collapse.

Kostroma, a city on the Volga river of around 230,000 people, is one of Russia’s oldest cities and famous for its medieval architecture and monasteries.

Russia, which frequently has a lax approach to safety rules, has seen a number of deadly fires at entertainment venues in recent years.

In 2018, a fire killed 60 people in a shopping mall in the Siberian city of Kemerovo.

In 2009, another blaze at a nightclub in the Urals city of Perm killed 156 people.