A woman seriously injured on Saturday afternoon after being buried by an avalanche at Piz Vilán in the canton of Graubünden died overnight, cantonal police said.
She was the fifth person to die from the snow slide that swept eight skiers down the eastern flank of the mountain at an altitude of about 2,200 metres.
Rescuers found three of the group were dead after being buried in the snow on the eastern flank of the mountain, police said.
Four seriously injured skiers were recovered and transported by helicopter to hospitals in Saint Gallen, Zurich and Chur, including another woman who died on Saturday evening.
One skier was able to dig himself out of the snow, while another member of the party of nine escaped the avalanche.
The skiers were all equipped with avalanche rescue equipment, police said.
Elsewhere, in Wildhaus in the canton of Saint Gallen near the Austrian border, a 26-year-old skiing off-piste on Saturday provoked a snow slide that sent him over a cliff, police said.
Also on Saturday, a 31-year-old Swiss man was killed by an avalanche while he was skiing off-piste in the Bernese Oberland, and in the same area a 28-year-old Swiss snowboarder was engulfed by snow and died.
The avalanche toll of eight people on Saturday was the worst in five years.
Another three off-piste skiers died on Thursday and Friday.
Up to 1.2 metres of snow has fallen in the region in recent days, and authorities had made repeated warnings of continuing avalanche dangers in many parts of the Swiss Alps and the Jura Mountains.