Seventeen miners were injured, including one seriously, when an earthquake hit the Bielszowice coal mine in southern Poland on Thursday, state-run news agency PAP said.
PAP quoted a spokesman for the mine owner, PGG, as saying the seriously injured man needed resuscitating, while the others had minor injuries.
The agency said the quake had a magnitude of 3 on the Richter scale.
All the miners were moved away from the threatened area, the spokesman was quoted as saying, although it was not immediately clear if they had been brought to the surface. The spokesman could not be reached for further comment.
In July three miners died after a tremor at PGG's Staszic coal mine in Katowice, in the deadliest incident in the country's mining industry this year.
Poland still generates most of its electricity from burning coal, but coal production has fallen in the past years due to lower investment and efforts to cost cuts.
Last year 21 miners died in mining industry accidents in Poland, official statistics show.
Euronews reached out to Polish authorities but officials were not immediately available to comment.