The former director of a Siberian coal mine has been sentenced to two years in prison over an accident that killed more than 50 people in November 2021, the Russian authoritiessaid Friday. Both miners and rescuers died after smoke filled the Listvyazhnaya mine in the Siberian region of Kemerovo following a gas explosion.

It was Russia's deadliest mining explosion in the past decade.Listvyazhnaya’s former director Sergei Makhrakov was detained with 16 other former managers and state safety inspectors as part of a criminal investigation into the mining accident. A Kemerovo region court on Friday found Makhrakov guilty of bribing employees of Russia’s environmental and technology watchdog Rostekhnadzor to overlook safety violations at the mine.Makhrakov pleaded not guilty.The other defendants in the case remain under investigation.Among those arrested include coal tycoon Mikhail Fedyayev — the politically connected ex-owner of the SDS-Ugol company that operated Listvyazhnaya — on charges of abuse of power. Authoritiesreleased Fedyayev from pre-trial detention and placed him under house arrest in 2022.Russia has seen a number of deadly mine blasts in recent years due to poor safety regulations, poor government oversight and aging Soviet-era equipment.