An underground earthquake left at least four miners dead and four missing at the Rudna mine in Polkowice, south-western Poland, according to state media.
The earthquake of magnitude 4.4 struck just after 9pm Tuesday local time, according to the US Geological Survey.
The quake was centred a shallow 10km (6.2 miles) underground, the USGS said, which would have magnified its effect at the mine belonging to state-run copper producer KGHM.
“There were 16 people in the danger zone. Some of them were walked out,” a spokeswoman for the company was quoted as saying by private radio RMF FM.
Among nine people evacuated, one man died, according to media reports. Rescuers also found another miner who had died underground.
Three miners were in stable condition in hospital with head and back injuries.
KGHM is one of the world’s largest producers of the copper and silver.