MOSCOW — A devastating fire swept through a Siberian coal mine Thursday, killing 52 miners and rescuers about 250 meters (820 feet) underground, Russian news reports said.
Hours after a methane gas explosion and fire filled the mine with toxic fumes, rescuers found 14 bodies but then were forced to halt the search for 38 others because of a buildup of methane and a high concentration of carbon monoxide fumes from the fire.
The state Tass and RIA-Novosti news agencies cited emergency officials as saying that there was no chance of finding any survivors.
The Interfax news agency cited a representative of the regional administration who also put the death toll from Thursday's fire at 52, saying they died of carbon monoxide poisoning.
A total of 285 people were in the Listvyazhnaya mine in the Kemerovo region of southwestern Siberia when a fire erupted and smoke quickly filled the mine through the ventilation system. Rescuers led to the surface 239 miners, 49 of whom were injured, and found 11 bodies.
Later in the day, six rescuers also died while searching for others trapped in a remote section of the mine, the news reports said.
Regional officials declared three days of mourning.
Russia's Deputy Prosecutor General Dmitry Demeshin told reporters that the fire most likely resulted from a methane explosion caused by a spark.
Explosions of methane released from coal beds during mining are rare but they cause the most fatalities in the coal mining industry.
The Interfax news agency reported that miners have oxygen supplies normally lasting for six hours that could only be stretched for a few more hours.
Russia's Investigative Committee has launched a criminal probe into the fire over violations of safety regulations that led to deaths. It said the mine director and two senior managers were detained.
President Vladimir Putin extended his condolences to the families of the dead and ordered the government to offer all necessary assistance to those injured.
In 2016, 36 miners were killed in a series of methane explosions in a coal mine in Russia's far north. In the wake of the incident, authorities analyzed the safety of the country's 58 coal mines and declared 20 of them, or 34%, potentially unsafe.
The Listvyazhnaya mine wasn't among them at the time, according to media reports.
Russia's state technology and ecology watchdog, Rostekhnadzor, inspected the mine in April and registered 139 violations, including breaching fire safety regulations.