(CNN) — At least six people were killed and another eight injured following an avalanche of ice in the Italian Alps, CNN affiliate Skytg24 said Sunday, citing first responders.

At least a dozen people are still missing following the collapse on Marmolada, the highest mountain in the Dolomites, Skytg24 also reported, citing rescuers.

The Alpine rescue service said via Twitter that an important segment of ice, also known as a serac, had collapsed on the Marmolada glacier, along the ascent to the summit.

It also said that all Alpine rescue stations in the area have been activated, including canine units and at least five helicopters.

At least six people were killed and another eight injured following an avalanche of ice in the Italian Alps, sources say https://t.co/CkwtjjG6fE

— CNN International (@cnni) July 3, 2022

A staffer at Castiglioni Marmolada Refuge, a local inn, witnessed the collapse of the serac, telling Skytg24 that he “heard a loud noise, typical of a landslide, then we saw a kind of avalanche composed of snow and ice and there I realized that something serious had happened.”

The collapse also took place amid record local temperatures, Skytg24 reported, reaching about 10 degrees Celsius (50 degrees Fahrenheit) at the mountain top.

Many parts of western Europe, including Italy, have been experiencing a long heatwave this past month.

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