An emergency services spokesman said a hailstorm in the Italian Alps killed at least six people and injured eight on Sunday.
Snow falls on Mount Marmolada, high above the Dolomites of Italy, near the valley of Punta Rocca, on a course often taken to reach its summit.
The disaster happened one day after recording a temperature of 10 degrees Celsius (50 degrees Fahrenheit) at an ice rink.
“Snow, ice and rocks attacked the entrance at a time when there were several groups, some of which were flooded,” emergency services spokeswoman Michela Canova told AFP.
Six people died at the scene, and eight others were injured.
Two injured were taken to a hospital in Belluno, one in a critical condition to Treviso and five to Trento.
“The number of climbers involved is not yet known,” Canova said.
He did not specify which race the victims belonged to.
Helicopters were flown to be part of the rescue operation.
Rescuers in the nearby Veneto region of northeastern Italy say they have evacuated all their Alpine groups, including sniffer dogs.
More falls are feared.
Photographs taken at the shelter near the scene show snow and stones piercing the mountain’s slopes and causing thunderstorms.
Some images visitors take to their cell phones show the gray snow sweeping everything in its path.
A mountain rescue team has released photographs of rescue workers and helicopters at the scene to take the victims from the village to the town of Canazei.
Their work was difficult because the bodies were trapped under snow and rocks.
A team of psychiatrists has been made available to support the victims’ relatives.
Experts quoted by Corriere Della Sera daily said they feared it would continue to snow.
Glacier expert Renato Colucci told Italian agency AGI that the situation “must be repeated,” as “for many weeks the Alps’ temperatures were above normal.”
He added that the latest warm temperatures produce large amounts of water from melting ice that accumulates beneath the ice and causes it to collapse.