Thirty-three other coal miners were hauled out unharmed from another part of the Russian mine on Saturday by rescuers who are dumping slag and metal pipes down another shaft to staunch the flow of floodwaters, four days after they rushed into the ageing Soviet-era colliery.

Interfax news agency earlier said the mine could be completely flooded by early Tuesday.

So far the rescuers have failed to make contact with the 13 men still missing in the Zapadnaya-Kapitalnaya pit near Rostov-on-Don in southern Russia.

Crews managed to dig through another 60 metres dug of earth from the adjacent Komsomolskaya Pravda shaft. Air inside the shaft was becoming thinner and freezing water gushed through at a rate of 22,000 cubic metres an hour.

Officials struck a note of hope saying there was enough air for the trapped miners to survive several more days despite rising carbon monoxide levels.

Ivan Mokhnachuk, head of Russia's coal miners' union, said
rescuers were planning for the "tunnel of hope" to break through to the tiny air pocket on Tuesday.

Mokhnachuk said the shaft should have been closed long ago
for safety reasons. "But there are no jobs for the miners who
have families that need to be fed," he said.

Relatives of those still trapped stood weary and freezing
outside the main shaft, wrapped in anoraks and fur hats.

"What am I to do with my children? He was our breadwinner,"
mumbled one woman, weeping and embracing her daughter.