A double avalanche has killed three people, including at least one rescuer, in the Diemtigtal valley about 40km (25 miles) south of the Swiss capital Bern.
The dead rescuer was a doctor who had been trying with others to help a group of skiers hit by the first avalanche when the second occurred, police say.
Six people were injured and it was not clear as night fell whether everyone had been accounted for.
A separate avalanche on Sunday killed a man in Switzerland's Valais canton.
A guide accompanying the victim was dug out of the snow and saved, the Tribune de Geneve newspaper reports.
The start of the ski season and heavy snowfall in recent days have prompted officials to warn of a heightened avalanche risk in the Swiss Alps.