Two ski resort workers have been killed in Morillon, a French Alps destination popular with Britons, by explosives they were using to spark an avalanche to keep the slopes safe for skiers.

Their deaths came as three German cross-country skiers died and a fourth was reported missing following an avalanche in western Austria.

The incident in Morillon occurred at around 8:30 am local time on Sunday as the workers were preparing the explosives at a height of 1,800 meters in the family resort in the Haut-Giffre valley.

Police said it had been confirmed that they were killed by the explosion and did not die after being caught up in the avalanche the blast set off.

They had been sent out to do their job in the Lanches sector of the resortbefore the ski slopes were opened to the public, after a night of heavy snowfall. Skiers had been warned that the risk of avalanche was at four on a scale of one to five.