Russian Vorkuta mourns for miners

Three days of mourning have begun in the city of Vorkuta in the Russian Arcticafter rescue workers failed to find more than twenty coal-miners trapped underground by Sunday's explosion at a mine.

Reports say despite a fire, blockages and poisonous fumes, the attempt to find the men is still going on, and special rescue workers have been sent from Moscow to help.

Four men are known to have died in the blast, which is thought to have been caused by methane gas; twenty-two others were brought to the surface.

Last month, almost seventy miners were killed by a similar explosion at a mine in Siberia.

From the newsroom of the BBC World Service