At least 13 miners died and 10 were wounded after a fire broke out in a coal mine in eastern Czech Republic, AFP reported on Friday, quoting a spokesperson. The fire started on Thursday afternoon at the CSM mine in Karvina city, about 300 km east of capital Prague.

“In total, we have 13 dead miners – 11 Polish and two Czech,” said OKD mining company spokesperson Ivo Celechovsky, adding that the Polish miners were from Poland-based Alpex mining company. OKD runs the mine and is controlled by the Czech state.

The explosion occurred at a depth of 880 m and was reportedly caused by burning methane. According to local media, the fire was still burning on Friday.

OKD Managing Director Boleslav Kowalczyk on Thursday said search operations had been abandoned due to conditions in the shaft, Reuters reported. “Unfortunately, we have reached a point where it was impossible to move forward, because there was a fire raging and zero visibility,” he said.

According to the Czech News Agency, the explosion is the worst mining accident in the country since 1990, when 30 people died in a fire at a mine near Karvina.

Czech Prime Minister Andrej Babis and his Polish counterpart Mateusz Morawiecki will visit the site on Friday. “The blast at the CSM mine is a huge tragedy,” Babis tweeted. “I’m in contact with rescuers, who are doing their best. We are ready to help immediately.”