BERLIN - Three miners died in eastern Germany Tuesday after an explosion at a potash mine operated by K+S sparked a gas leak, the owners of the site said.
The incident occurred after a controlled blast released high concentrations of carbon dioxide at the Unterbreizbach shaft of the Werra potash mine in Thuringia state.
Four other miners were also underground at the time of the incident, which happened 700 metres (2,300 feet) below the surface.
"Three are dead, the four others are unharmed," a spokeswoman for the industrial site said.
The three who died were aged 24, 50 and 56, K+S said in a statement.
"Having a carbon dioxide leak is an everyday occurrence," said spokesman Ulrich Goebel for mine operator K+S Potash, a unit of K+S, the world's biggest salt maker.
"But it is highly unusual to have such a large quantity seep out so that the gas penetrates the mine shaft and escapes above ground."
Two mines and an above-ground work area were "protectively evacuated", the company said.
K+S Potash operates six mines in Germany, producing salt for the agricultural, healthcare and food industries.