Hopes fade

Liu Dezheng, the spokesman for the rescue headquarters, said that one of the sections in particular was "surrounded by perils."

"The chances of survival of those workers trapped in that section is remote," he said.

On Thursday, hundreds of rescue personnel working underground to find the missing workers were forced to retreat when water began seeping through a ceiling in the shaft.

Flooding water equivalent to more than the volume of 55 Olympic swimming pools  trapped 153 workers underground in the unfinished Wangjialing mine in late March.

The flood is the latest deadly accident to embarrass the government, which has responded to similar disaster situations in recent years with public promises to improve safety and close down dangerous mines.

More than 2,600 miners were killed in China last year, according to government figures, although labour activists say the actual numbers are probably far higher.