On the same day a separate avalanche near Chamonix in the Haute-Savoie region to the north killed a Swiss skier, according to the public prosecutor's office in nearby Bonneville.

The Norwegian victims were part of a group of seven skiers caught in the avalanche in Val-Cenis, on the border with Italy.

Three were killed on the spot while another, a woman, died after being taken to hospital in Grenoble with a cardiorespiratory arrest and severe hypothermia, an official in the Savoie prefect's department said.

The remaining three were unharmed.

All were equipped with avalanche beacons as they were engaged in off-piste ski touring, the mayor of Val-Cenis, Jacques Arnoux, told AFP.

"It was an avalanche of great size which was triggered outside the ski area," he added.

A team of 10 high-mountain rescue specialists joined in the operation, according to a police source.

The victim in the Haute Savoie avalanche on Wednesday was a 30-year-old woman who was skiing off-piste on the north face of the Aiguillette des Posettes in the Mont Blanc massif, according to the office in Bonneville.

She was with her father, who was unhurt, and her brother, who was taken to the hospital for tests.

All three were equipped with transceivers and anti-avalanche airbags, the prosecutor's office added.