Image copyright Reuters Image caption Sibirsk Prospekt is in shock after the tragedy
More than a dozen miners are believed to have died in a methane gas explosion at a Russian mining complex near the city of Sibirsk, reports say.
Several others, including the owner of the mine, are said to be missing and are feared dead.
According to the Interfax news agency, rescue workers have been called in to try to reach workers in the Mashaia Mine.
Parts of the compound collapsed and at least one helicopter has been sent to the scene.
The incident happened on Monday morning in the Grigory mine, said Interfax.
“The site has been completely devastated,” said Oleg Tyurin, the governor of the Voronezh region, which includes Sibirsk.
“The people are in complete panic, and they are not responding to our attempts to convince them to stay on the surface.
“There are still a few miners trapped… there are 30 to 35 miners on the surface and they are all in danger.”
Russia’s Investigative Committee has started an inquiry into the accident, reported CNN.
The neighbouring Itsukov mine, owned by a company linked to the owner of the Grigory mine, Sibirgaz, has said its entire staff are safe.
The government has demanded that the miner explain why the safety management was weak.
Image copyright Getty Images Image caption A major wave of earthquakes struck Ukraine in 2014
The Grigory mine was not working at the time of the incident.
Other mining accidents this year include a fatal blaze at a coal mine in Haryana state, in India, that killed 15 people in April.
Last month, the Russian parliament passed a new mining law aimed at improving safety.