In Canada, three people are dead while others are still buried under piles of snow, after an avalanche hit a snowmobile competition near Revelstoke, British Columbia.

Police have put the number of spectators at the event at around the 200 mark.

While snowmobilers watched the competitors motor around Boulder Mountain on Saturday, the avalanche hit, carrying some of the snowmobilers as much as 200 metres down the mountain.

It is not known how many spectators may have been caught in the avalanche but rescuers have been out trying to find survivors and deceased victims.

Revelstoke is about 300 kilometres west of Calgary, Alberta.

It is believed recent heavy snowfall triggered the avalanche.