Rescue workers in southern Russia have begun lifting to the surface some of the 46 coal miners trapped in a flooded shaft since Thursday. So far, 33 have been rescued. Russian authorities say contact has been made with most of the miners, but 13 are still unaccounted for, and it is unknown if they are alive.

Russian officials say a rescue team went down into the mine, and managed to reach the flooded shaft where the miners were trapped. A small elevator cage then started taking the miners to the surface, two or three at a time.

Relatives, blocked by police cordons, watched the rescue operation outside the mine. Doctors would not allow them to speak with rescued miners, until they had completed medical checkups and treatment.

The survivors were immediately taken to a nearby hospital, where at least one was reported in serious condition.

The miners were trapped in a shaft filled with knee or waist-high water for nearly two days, with no electricity, low batteries, no food and very little air.

A total of 71 miners were reported working 800 meters underground in the Zapadnaya mine when water from a subterranean lake started leaking into the mine. About 25 managed to escape to other pits, and reach the surface before water blocked the way out for the others, who were trapped in the shaft.

In the last two days, trucks have dumped loads of earth and rock into the mine to try to plug the leak, while rescue workers dug tunnels from a nearby shaft. Then the emergency teams abandoned their efforts to tunnel through to the miners, and started instead to drain the water from the shaft.

According to Russian media reports, the accident was the second of its kind in the Zapadnaya mine this year. In February, water flooded the mine, which was built more than 60 years ago, but no one was inside at the time.

According to the Independent Coal Miners' Union, 166 miners have been killed on the job in the last two years.

The worst disaster occurred in December 1997, when more than 60 workers died instantly in a methane explosion that ripped through a pit in Siberia.