Rescue teams have confirmed the death of one Polish coal miner and can see another miner trapped after an natural disaster, but it is not known if he is dead or alive, the chief executive of mine owner JSW said.
Jablonska-Bajer said four miners were quickly taken to the surface but contact was lost with seven others who were 2,950 feet underground, preparing a new corridor for extraction work.
Eight teams of rescuers were at the Jastrzebie Coal Company site near the Czech border, trying to locate the missing miners.
Rescuers battled in the early hours of Sunday to reach four coal miners who remained trapped almost one kilometre (0.6 mile) underground in southern Poland after an natural disaster. "There are three rescue units more joining the operation which is going on", said JSW Coal's Daniel Ozon.
Prime Minister Mateusz Morawiecki, who arrived at the mine Saturday night, said the rescuers were working nonstop and using the best equipment to reach the missing miners, but they were running into blocks of rubble. Ozon said emergency workers were pumping air into the affected area to lower the level of methane gas before they can safely move ahead.
Ozon said that the quake had a magnitude of 3.5 to 4.0. President Andrzej Duda was on his way to the town.
Coal mining is a major industry in Poland.
Two miners were rescued on Saturday after the tremor caused part of the tunnel where they worked to collapse. It was not clear if the miner was dead or alive. The Main Statistical Office says some 65.8 million metric tons, (58.7 million tonnes), of coal were extracted previous year, some 4.8 million tons less than in 2016.
Still many of Poland's mines are unsafe, with methane gas that has led to a number of deadly explosions and cave-ins. So far this year, five miners including Sunday's casualty have been killed at different mines, according to the State Mining Authority.