At least 52 people are dead after a Russian coal mine fire in Siberia — the deadliest in over a decade

• 46 miners and 6 rescuers were killed in a Siberian coal mine fire.
• It's the deadliest coal mining disaster Russia's seen in more than a decade.

A coalmine fire in Russia's vast Siberian coal basin has suffocated, trapped, and killed 52 people, leaving "no survivors" underground, a source told Russian state media on Thursday.

The Listvyazhnaya coalmine, in Belovo, caught fire on Thursday, spreading smoke throughout the facility. The fire was likely caused by a methane explosion, Russian state media agency Tass said.

At least 46 miners and six rescue personnel died of carbon monoxide poisoning, as they were trapped more than 800 feet underground, the Associated Press said. 239 other workers managed to escape the disaster, but at least 49 of them were taken to the hospital, with issues including smoke poisoning, per the BBC.

"Impact. Air. Dust. And then, we smelled gas and just started walking out, as many as we could," miner Sergey Golubin said on TV after he escaped the fire. "We didn't even realize what happened at first, and took some gas in."

Three people — including the director of the coal mine and his deputy — have been arrested on suspicion of violating industrial safety rules, Reuters reported.

"The president offers deep condolences to the families of coal miners who died," Russian President Vladimir Putin's spokesman Dmitry Peskov said.

The Kemerovo region, which is Russia's coal capital, has declared three days of mourning. This is the deadliest explosion to hit the area since 2010, when more than 90 people were killed at the Raskadskaya mine.