Search and rescue efforts at the Listvyazhnaya coal mine in Russia have been suspended again after rising gas levels made the environment unsafe.

AT 15:17 local time, Sergei Tsivilev, governor of the Kemerovo Oblast region, said there was a risk those searching for survivors could be poisoned by the "sharp increase in the concentration of gases in the mine."

He said work will resume only "if the situation allows" and in "a safe environment." The rescue was suspended on 25 November, hours after the explosion, for the same reason.

However, Tsivilev reiterated that authorities are working to increase the amount of nitrogen and carbon dioxide and prevent another explosion.

A gas explosion on 25 November at the mine killed 52 miners, some of whom were reportedly trying to save others. Five people connected to the running of the mine have been charged with causing death by negligence.

Nikolai Medvedev, general director of the All-Russian state emergency service, said it was impossible to lift more bodies from the mine at this time due to the threat of another explosion.