Three miners have been killed by falling rocks after a minor earthquake at a copper mine in southwestern Poland.

A spokesman for the KGHM Rudna copper mining company, Dariusz Wyborski, says the earthquake struck Thursday about 1,000 meters (yards) below ground and could be felt in a radius of 12 miles (20 kilometers).

He says rescuers brought 24 miners to the surface, some of whom had to be hospitalized, but none of their injuries were life threatening.