Late Tuesday morning, "a sixth person died. The deceased was a 52-year-old Bulgarian woman," police in Valais canton said in a statement.
Bad weather in the Pigne d'Arolla area of the Swiss Alps on Sunday had caught the group of skiers by surprise. The group had set out from the Dix rest-stop and had intended to make it to Vignettes to sleep, trekking along a route called The Serpentine.
The manager of a rest-stop in the remote mountain region sent out a call for help at dawn on Monday, triggering a major relief operation that involved seven helicopters, police said.
One person was found dead on the scene, and was believed to have died in a fall. Three others died soon after they reached hospital, followed by the fifth death late Monday and another on Tuesday.
The two most recent casualties were most likely among the five initially listed in critical condition by police. Others in the group were merely suffering from "mild hypothermia". The victims were Italian, French and German nationals, police said, adding that efforts were under way to formally identify them.
All the families had been informed of the tragedy, police said. Police said separately that the bodies of two climbers, aged 21 and 22, were found further east Monday, in the Alps in Bern canton, after the alert was sounded late Sunday but the bad weather foiled rescue efforts.