Thursday's blast occurred 2,625 feet below ground at the CSM hard-coal mine near Karvina city, close to the Polish border.
OKD, the company that operates the CSM mine, said 11 of those killed were Polish miners provided by a contractor agency, while two were Czech, CNN reported.
A further 10 miners were injured in the blast, with one in a critical condition, according to the Czech national news agency CTK.
The explosion devastated large areas of the mine. OKD's Managing Director, Boleslav Kowalczyk, said search and rescue operations had to be called off because of poor conditions in the mine.
"Unfortunately, we have reached a point where it was impossible to move forward because there was a fire raging and zero visibility," he said in a statement.
Czech Prime Minister Andrej Babis visited the mine with his Polish counterpart Mateusz Morawiecki.
"The blast at the CSM mine is a huge tragedy," Babis tweeted, adding that the country's Parliament will observe a minute's silence for the victims on Friday.
Morawiecki called the incident "a huge tragedy for all Poles and Czechs".
"On this difficult day, we strongly show our solidarity and sense of national community," he said.
The disaster is the worst mining accident to occur in the Czech Republic since 1990, when 30 miners died in a fire in another mine near Karvina.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
This website uses cookies.