The accident which occurred at a depth of 880 metres at the CSM mine in the city of Karvina, also injured 10 others. Eleven of those killed were from neighbouring Poland.
At least 13 miners were killed and 10 were injured after a fire, caused by burning methane, erupted in a black coal mine in the east of the Czech Republic, a spokesman for the OKD mining company said Friday.
"In total we have 13 dead miners, 11 Polish and two Czech," OKD spokesman, Ivo Celechovsky, said.
The accident occurred at a depth of 880 metres at the CSM mine in the city of Karvina, about 300 kilometres east of the capital Prague, on Thursday afternoon.
Rescuers found five dead miners on Thursday and reported eight missing. All of them were also found dead.
Celechovsky said the fire was still burning, with rescuers building barriers to stop it from spreading.
He added they would work there at least until Sunday.
Nada Chattova, a spokeswoman for the hospital in the nearby city of Ostrava, said two men had been treated at its burn centre.
"One was brought in by a helicopter, he is still in a critical condition. The other one is in a stable condition and his life is not in danger," she said.
One miner with a lighter injury was taken to a hospital in Karvina and seven were treated on the spot, also with lighter injuries, Czech media said.
"The blast at the CSM mine is a huge tragedy," tweeted Czech Prime Minister Andrej Babis, who will travel to the site on Friday morning along with his Polish counterpart Mateusz Morawiecki.
The prime ministers spoke on the phone after the accident, Morawiecki said in a tweet, adding that Polish rescuers had also been sent to the mine.
Celechovsky said on Thursday the dead Polish miners were from the Poland-based Alpex mining company.
'One big family'
"We're one big family, it's a terrible tragedy," a Czech miner told the local Polar TV.
"I was supposed to be there, I work with these teams every day. They sent me to work somewhere else today," said a Polish miner.
"I feel like crying," he said.
OKD, which runs the mine, is controlled by the Czech state and expects to extract about five million tonnes of coal this year.
The accident is the most serious one at a Czech mine since 1990 when 30 miners died following methane combustion at another mine in Karvina.