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Thirteen miners have died and about 10 others were injured after a blast at a mine in the Czech Republic.

Thirteen miners, including 12 Poles and one Czech, were killed in a methane blast more than 800 meters (875 yards) underground late on Thursday.

The explosion devastated areas of the CSM hard coal mine near the town of Karvina, which is located 300 kilometers (200 miles) east of Prague, according to the state-run OKD mining company, which operates the mine.

A network of methane sensors deployed in the mine had not detected anything unusual prior to the blast, OKD managing director Boleslav Kowalczyk said.

Worst mining disaster

"The blast at the CSM mine is a huge tragedy," tweeted Czech Prime Minister Andrej Babis. He will travel to the site later today along with his Polish counterpart Mateusz Morawiecki.

"I wish to express words of deepest sympathy to all the close victims of the mining disaster in Karvina," Morawiecki said. "This is a huge tragedy for all Poles and Czechs."

Polish President Andrzej Duda declared Sunday a day of national mourning. He expressed his condolences on Twitter, saying "O Lord, keep the families of the miners in your care. RIP."

The accident is the worst mining disaster in the Czech Republic since 1990, when 30 miners died in a fire at a mine in the same region.

Zero visibility

The deceased Polish miners were from the Poland-based Alpex mining company.

"We're one big family, it's a terrible tragedy," a Czech miner told the local Polar TV.

Czech media reported on Friday that the fire had not been put out yet.

OKD managing director Boleslav Kowalczyk said the search of the scene had had to be abandoned due to conditions in the shaft.

"Unfortunately, we have reached a point where it was impossible to move forward, because there was a fire raging and zero visibility," he said.