Six miners have been injured in Polish copper mining company KGHM’s Rudna mine in western Poland after an earth tremor. “The tremor occurred at 2 am” on Tuesday, KGHM’s Jolanta Piątek said.

“There were six miners in the vicinity who made it to the surface on their own.”

The workers’ injuries are minor but they remain in hospital for observation, Piątek added.

Mining has been suspended in the section of mine where the tremor occurred.