The death toll in Monday's coalmine blast in Siberia has risen to 81, while 42 miners still remain accounted for.

83 of the 200 miners have been rescued so far from the Ulyanovskya mine in Novokuznetsk, the largest coal-producing centre in the Kemerovo region, a report by RIA Novosti said.

Explosions are not uncommon in Russia's crumbling coal mining industry. But the Ulyanovskya mine was only opened in 2002. It produces 3 million metric tons of coal annually and its reserves total 210 million metric tons.

The explosion was probably caused by the collapse of the mine roof and methane penetration, Kemerovo regional authorities said.