MILAN -- An avalanche struck high in the Italian Alps on Saturday, killing six backcountry skiers as others looked on in horror as a swath of snow hundreds of metres wide cascaded down.

Helicopters ferried both the survivors and the bodies back to the valley floor from the avalanche site, located just over a 100 metres shy of Monte Nevoso's 3,358-meter (11,017-foot) peak. The mountain is not far from the Austrian border in Italy's Alto Adige region.

The dead were among a group of backcountry skiers climbing above tree line to the mountain crest and then skiing down. The dynamics of the midday avalanche still were not clear.

Italian financial police, who have a helicopter, and local police confirmed the six deaths.

Financial police Brig. Albert Castlunger said the survivors had summoned rescuers, who responded with three helicopters and dozens of search-and-rescue workers who deployed dogs and used poles to probe the snow for more possible victims.

He put the number of injured skiers at four, while financial police Capt. Alessandra Faletti told RAI state television that 15 people in all had been on the mountain at the time of the avalanche.

The news agency ANSA, quoting rescuers, said one person was injured in the avalanche and eight others survived unharmed in a group that included Austrians and Italians.

It was not immediately possible to rectify the different accounts.

The high altitude and the number of people involved complicated the rescue, Rafael Kostner, the head of the rescue operation, told ANSA.

"The helicopters are having difficulty safely reaching altitudes above 3,000 metres," Kostner said. "They fly with very little fuel and all unnecessary gear is left on the ground."

Bolzano province's avalanche report forecast the avalanche risk for Saturday as moderate, a two on a scale of 1-to-5. It said avalanches were possible on leeward slopes near ridges with the risk rising throughout the day.