In the worst mining accident in Russia in years, 52 people died in western Siberia.

The state agencies Tass and Ria Nowosti reported this on Thursday evening, citing the ambulance service.

Among them were six rescue workers who died during search work in the mine.

It is unclear whether there are still 35 workers in the mine who are out of contact.

The rescue work was temporarily interrupted due to the risk of explosion.

In addition, according to the Ministry of Civil Protection, contact with several rescue workers broke off.

A total of 239 workers were rescued from the “Listwjaschnaja” shaft in the Kuznetsk coal basin (Kuzbass), more than 49 of them had to be treated in hospitals, as the governor announced.

An explosion had occurred in the mine in the morning for an initially unknown cause.

Ziwiljow started a three-day mourning in the region - from this Friday to Sunday.

The condition of the miners in the shaft was initially unclear.

The mine tunnels were heavily filled with smoke, it was said.

The workers could not save themselves.

This was announced by Governor Ziwiljow after a video conference with Russian Civil Protection Minister Alexander Chuprijan.

The minister also traveled to the region.

Explosion at a depth of 250 meters

According to the investigators, the 47-year-old mine director, his deputy and a department head were arrested.

You would have to answer for violating work regulations.

Ziwilev visited the injured in the hospital in the evening and, according to his own statements, met with family members of the miners.

The explosion is said to have occurred at a depth of 250 meters.

Russian President Vladimir Putin expressed condolences to the relatives of the victims of the "tragedy" and ordered aid to the bereaved and survivors.

“Unfortunately, the situation is not getting any easier.

There is also a danger to the lives of the rescue workers, ”Putin said.

"We hope that it will be possible to save as many people as possible."

Working in coal mining in Russia is considered life-threatening.

Serious accidents occur time and again due to violations of elementary safety regulations.

Methane gas, for example, often explodes.

The highly flammable mine gas is released during work in the mining industry and, if there is poor ventilation, it collects in the shafts and routes.