Watch: Six hikers killed after piece of glacier breaks loose in Italian Alps
At least six hikers have been killed and nine injured after a chunk of a glacier broke loose in the Italian Alps.
Local authorities fear more could be dead as around 15 people are missing in the Dolomite mountains in northeastern Italy.
Of the hospitalised survivors, two were in grave condition, authorities said.
The chunk of ice, from the Marmolada glacier, slammed into hikers on a popular trail.
National Alpine and Cave Rescue Corps said in a tweet that the segment broke off near Punta Rocca (Rock Point), "along the itinerary normally used to reach the peak".
"We saw dead (people) and enormous chunks of ice, rock," rescuer Luigi Felicetti told Italian state TV.
Rescuers said blocks of ice were continuing to tumble down.
The search by helicopter and dogs for any more victims or missing was halted for the night while rescuers evaluated the risk that more of the glacier could break off, Walter Cainelli told state television.
The SUEM dispatch service, which is based in the nearby Veneto region, said 18 people who were above the area where the ice struck would be evacuated by the Alpine rescue corps.
Other hikers might be able to get down by themselves using the peak’s cable car, authorities said. Some hikers were tied together by rope, according to local emergency services.
SUEM said the avalanche consisted of a "pouring down of snow, ice and rock". The detached section is known as a serac, or pinnacle of ice.
Dubbed the "queen of the Dolomites," Marmolada rises about 3,300 metres (about 11,000 feet) and is the highest of the 18 peaks in that eastern range of the Italian Alps, offering spectacular views of other Alpine peaks.
"The temperatures of these days clearly had influence" on the glacier’s partial collapse, Maurizio Fugatti, the president of Trento Province, which borders Marmolada, told Sky TG24 news.
But Corps spokesman Walter Milan told the Associated Press (AP) that high heat, which soared unusually above 10C on Marmolada’s peak in recent days, was only one possible factor in Sunday’s tragedy.
"There are so many factors that could be involved," Mr Milan said. Avalanches in general aren’t predictable, he said, and heat’s influence on a glacier "is even more impossible to predict."
The Mediterranean basin, shared by southern Europe, the Middle East and northern Africa, has been identified by UN experts as a "climate change hot spot," likely to suffer heat waves and water shortages, among other consequences.