Three people have died and two are injured following a methane blast at Darkov mine in Karvina, north Moravia, which is owned by New World Resources' Czech mining subsidiary OKD.
The blast occurred in the underground mine, around 300km east of Prague, while drifting a tunnel.
During the process, it is thought that rocks had fallen, igniting methane that had been released into the air.
Prague Post quoted National Mining Administration spokesman Bohuslav Machek saying that a seismic phenomenon occurred and immediately methane was released.
Machek said: "As a result, the mixture of methane and air was lit up."
An investigative committee formed by members of the District Mining Authority in Ostrava, Darkov Mine management, OKD management, the OKD Trade Unions representatives, and the police of the Czech Republic are investigating the accident.
Darkov mine is estimated to have a coal reserve of 8.6 million tonnes and produces about 1.65 million tonnes of semi-soft coking or thermal coal.
The mine is one of four of OKD's hard coal mines, the others being Karvina, Paskov and CSM.