OSINNIKI (Russia) - A gas explosion at a Siberian colliery on Saturday killed up to 40 miners, officials said.

Rescue teams pushed their way down two routes into a vast shaft to try to find about 20 others missing underground. The explosion ripped through the mine early on Saturday as 54 miners who had worked through the night were nearing the end of their shift.

Natalya Katunina cries in the village of Vysokiy, in the Kemerovo region of western Siberia on Tuesday, April 13, 2004 during the funeral of her husbend Alexander, who died after a methane blast at the Taizhina coal mine. The death toll has reached 45 following Saturday's explosion. (AP Photo/Ivan Sekretarev)

With the rescue teams working non-stop, Itar-Tass news agency said 30 miners had been found dead in Siberia's Kemerovo district in the heart of the Kuzbass coalfield where accidents are a regular occurrence.

The blast left a pile of rubble that blocked rescuers, forcing some of them to resort to a longer route to the epicenter through a neighboring mine, while the others tried to dig through the blasted shaft.

Eight miners were rescued from the Taizhina mine on Saturday, said Mr Valery Korchagin, an emergency department spokesman in the Kemerovo region of western Siberia.

Four of the rescued miners were injured and two of them were hospitalized with burns, he added.

Only 16 of the bodies had been retrieved by yesterday morning. The bodies were badly disfigured, making identification very difficult. A handful of rescuers, their faces grim and blackened by coal dust, emerged from the adjacent mine.

They said they had been working with shovels and just their hands to clear the rubble. Asked if there was hope of finding anyone alive, one of the men just shook his head solemnly.

As the nation celebrated Easter, the most important holiday for Russia's predominant Orthodox Christian faith, the trapped miners' fearful relatives gathered in the mine's administration building to await news.

Russian state television showed brief pictures of a sobbing woman rushing away after apparently learning of a relative's death in the mine.

Kemerovo Governor Aman Tuleyev, who was overseeing the rescue operation, said on Russian television that the shortest path to the blast site was blocked by what appeared to be impassable rubble.

Itar-Tass said the roundabout path that rescuers were trying to use was 5km long.

The blast in the mine occurred at a depth of 560m, and was believed to have been caused by a methane build-up, a duty officer at the Kemerovo regional emergency department said.

The shaft was filled with carbon dioxide, the Interfax news agency reported.

Accidents are common in the Russian coal industry and miners stage frequent protests over wage delays and declining safety standards.

In September 2002, one miner at Taizhina was killed and two others were seriously injured when the roof of a ventilation shaft collapsed during reconstruction work, showering them with rocks.

According to Itar-Tass, the mine in the city of Osinniki was built in 1998 on the foundation of a closed mine, and the equipment appeared to be run-down. A methane explosion killed five miners in the Kemerovo region in January, and an investigation indicated that a methane blast - possibly sparked by a short circuit - caused a ceiling collapse that killed 12 workers at another mine in the region last June.

In October last year, icy water flooded a mine in southern Russia, killing two men. Rescuers freed 69 others.