Russia sent more than 160 rescuers to a remote Siberian mountainside on Tuesday in a frantic hunt for six teenage boys who are feared dead after being trapped by an avalanche.

The search with sniffer dogs was however hampered by bad weather and the risk of further avalanches, the emergency situations ministry said.

The boys aged 14 to 18 were overtaken by the  avalanche Sunday as they descended the Ak-Bashtyg mountain in the Tyva region of southern Siberia, the central Investigative Committee said.

One member of the group, junior kickboxing champion Anton Salchak, 17, escaped and was able to raise the alarm.

"We have searched 700 square metres but so far with no result," the head of the Siberia's emergency situations centre, Vladimir Svetelsky, told the ITAR-TASS news agency.

The peak is one of the highest in the region at  3,250 metres (10,662 feet).

Sholban Kara-ool, leader of the sparsely populated Buddhist region of Tyva that borders Mongolia, travelled to the scene Tuesday.

"The chances of success in such conditions are small, but we are not losing hope. We will do everything possible to save the children," the region's deputy leader, Vitaly Bartyna-Sady, said Monday.