Kacsper Pempel/REUTERS
A miner works at copper ore at Polkowice-Sieroszowice mine, part of KGHM, in Polkowice near Lubin, southern-western
A spokesman for mine operator KGHM told Reuters that there had been no contact with the miners for two hours.
They are reportedly trapped 600 meters below ground at the Rudna copper mine, 250 miles southwest of Warsaw.
The 4.7-magnitude earthquake struck at around 5:30pm EST 49 miles northwest of Wroclaw, according to the USGS, BNO News' @mpoppel tweeted earlier today.
He also tweeted that Polish news sources are reporting that three other miners were able to escape from the mine.