Miners carry a dead body to a vehicle at a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Miners carry a dead body to a funeral vehicle at a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Rescue workers carry a body outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Rescue workers walk near family members of miners outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Rescue miners walk by family members of miners outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Family members of miners react outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Family members of miners react outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Family members of miners react outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Miners and family members are seen outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Miners carry a dead body to a funeral vehicle at a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Miners carry a dead body to a funeral vehicle at a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Rescue workers are seen outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Workers and family members are seen outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Family members of miners are seen outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Workers and family members are seen outside a coal mine, after a shaft collapsed killing at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

Rescuers work to try and determine how many miners are trapped inside a collapsed shaft at a coal mine, after an accident that killed at least eight miners, according to RTS state television, in Sokobanja, southern Serbia, April 1, 2022. REUTERS/Antonio Bronic 

An aerial view shows a mining and processing plant and the premises of the Listvyazhnaya coal mine following a recent deadly accident in the Kemerovo region, Russia, November 28, 2021. Picture taken with a drone. REUTERS/Maxim Shemetov 

An aerial view shows the premises of the Listvyazhnaya coal mine following a recent deadly accident in the Kemerovo region, Russia, November 28, 2021. Picture taken with a drone. REUTERS/Maxim Shemetov 

A truck of the Russian Emergencies Ministry transporting a with a tank of nitrogen on the premises of the Listvyazhnaya coal mine following a recent deadly accident in the Kemerovo region, Russia, November 28, 2021. REUTERS/Maxim Shemetov 

People gather neat an entrance to the premises of the Listvyazhnaya coal mine following a recent deadly accident in the Kemerovo region, Russia, November 28, 2021. REUTERS/Maxim Shemetov 

People gather neat an entrance to the premises of the Listvyazhnaya coal mine following a recent deadly accident, with a makeshift memorial seen in the foreground, in the Kemerovo region, Russia, November 28, 2021. REUTERS/Maxim Shemetov 

A view shows a makeshift memorial outside the premises of the Listvyazhnaya coal mine following a recent deadly accident in the Kemerovo region, Russia, November 28, 2021. REUTERS/Maxim Shemetov 

Police officers stand guard on the premises of the Listvyazhnaya coal mine following a recent deadly accident in the Kemerovo region, Russia, November 28, 2021. REUTERS/Maxim Shemetov 

Police officers stand guard on the premises of the Listvyazhnaya coal mine following a recent accident in the Kemerovo region, Russia, November 28, 2021. REUTERS/Maxim Shemetov 

People lay flowers at the Alley of Miners' Glory to pay tribute to the miners and rescuers killed in an accident at the Listvyazhnaya coal mine, in the settlement of Gramoteino in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

A fire truck drives past the administrative building of the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

Governor of the Kemerovo region Sergei Tsivilyov leaves the territory of the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

Svetlana Borisovna, mother of the miner who died in Thursday's mine accident, reacts at the entrance to the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

A view shows the administrative building of the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

Governor of the Kemerovo region Sergei Tsivilyov speaks to the media at the entrance to the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

Governor of the Kemerovo region Sergei Tsivilyov speaks to the media at the entrance to the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

Governor of the Kemerovo region Sergei Tsivilyov speaks to the media at the entrance to the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

A view shows the facilities of the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

Svetlana Borisovna, mother of the miner who died in Thursday's mine accident, reacts at the entrance to the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

Vehicles are seen near the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

A stop sign is seen at the entrance to the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

A view shows the administrative building of the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

A view shows the administrative building of the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

Police officers patrol at the entrance to the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

Vehicles of the Russian Emergencies Ministry drive near the Listvyazhnaya coal mine following Thursday's mine accident, in the Kemerovo region, Russia, November 27, 2021. REUTERS/Maxim Shemetov 

People walk after laying flowers at the monument "In Memory of Kuzbass Miners" to pay tribute to the miners and rescuers killed in an accident at the Listvyazhnaya coal mine in the Kemerovo region, in Kemerovo, Russia, November 26, 2021. REUTERS/Alexander Patrin 

People walk to lay flowers at the monument "In Memory of Kuzbass Miners" to pay tribute to the miners and rescuers killed in an accident at the Listvyazhnaya coal mine in the Kemerovo region, in Kemerovo, Russia, November 26, 2021. REUTERS/Alexander Patrin 

People walk to lay flowers at the monument "In Memory of Kuzbass Miners" to pay tribute to the miners and rescuers killed in an accident at the Listvyazhnaya coal mine in the Kemerovo region, in Kemerovo, Russia, November 26, 2021. REUTERS/Alexander Patrin TPX IMAGES OF THE DAY 

People lay flowers at the monument "In Memory of Kuzbass Miners" to pay tribute to the miners and rescuers killed in an accident at the Listvyazhnaya coal mine in the Kemerovo region, in Kemerovo, Russia, November 26, 2021. REUTERS/Alexander Patrin 

A stop sign is seen at the entrance into mine territory following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

A vehicle of the Russian Emergencies Ministry drives into the territory of the mine following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

A vehicle of the Russian Emergencies Ministry drives near the mine territory following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

People gather near an entrance into mine territory following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

Specialists of the Russian Emergencies Ministry are seen near an entrance into mine territory following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

Vehicles of Russian emergency services are seen at the mine territory following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

People gather at the entrance into mine territory following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

A woman stands near an entrance into mine territory following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

People gather near an entrance into mine territory following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

People gather near an entrance into mine territory following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

Specialists of the Russian Emergencies Ministry enter the territory of the mine following an accident at the Listvyazhnaya coal mine in the Kemerovo region, Russia, November 26, 2021. REUTERS/Alexander Patrin 

Graphic shows the area of the explosion at the Hushan Gold Mine and from where the miners were rescued after clearing the blockage in the main shaft. 

A total of 22 workers were trapped underground in the Hushan gold mine on the outskirts of Yantai, on China’s eastern coast, following the January 10 blast 

Rescuers work at the Hushan gold mine where workers were trapped underground after the Jauary 10 explosion, in Qixia, Shandong province, China January 22, 2021. REUTERS/Aly Song 

Medical workers in protective suits wait to collect swabs from rescue workers for nucleic acid testing following the coronavirus disease (COVID-19) outbreak, at the Hushan gold mine where workers were trapped underground after the January 10 explosion, in Qixia, Shandong province, China January 22, 2021. REUTERS/Aly Song 

Rescuers work at the Hushan gold mine where workers were trapped underground after the Jauary 10 explosion, in Qixia, Shandong province, China January 22, 2021. REUTERS/Aly Song