Unusually heavy snowfall and a high risk of Alpine avalanches have stranded 13,000 tourists in the Swiss resort of Zermatt at the base of the famed Matterhorn mountain.

With nearby roads, trains, cable cars, ski slopes and hiking trails into the town closed, authorities deployed helicopters to ferry some tourists to a nearby village to escape the snowbound Alpine valley.

A police official in Zermatt, a tourist magnet for backpackers and millionaires alike, said the helicopter journey to the village of Taesch takes around three minutes.

Tourists wait in line at the heliport of Air Zermatt for a flight by airlift into the valley to Raron, in Zermatt (Dominic Steinmann/Keystone via AP)
Tourists wait in line at the heliport of Air Zermatt for a flight by airlift into the valley to Raron, in Zermatt (Dominic Steinmann/Keystone via AP)

The official said the so-called air bridge can transport about 100 people an hour, conditions permitting.

Only tourists who requested the air bridge were being ferried out, the official said, insisting it was not an official evacuation.

Swiss state-backed broadcaster SRF showed images of several people wheeling their luggage to three helicopters on an icy plateau.

Bulldozers were ploughing through the snowdrifts in Zermatt so streets could be salted.

One local hotelier said authorities were setting off controlled explosions to help clear away the piled-up snow that had coated roads and rails.

Janine Imesch of the Zermatt tourism office said power has been restored after a temporary outage.

She said no people were at risk because authorities had shut down access to the nearby ski slopes and hiking trails a day earlier.

Young skiers enjoy the snow in Zermatt (Leander Wenger/Keystone via AP)
Young skiers enjoy the snow in Zermatt (Leander Wenger/Keystone via AP)

“There is nothing to panic about, everything is fine,” she said. “Only the ski areas are closed. In the village, the atmosphere is relaxed.”

Romy Biner, head of Zermatt town council, told SRF the airlift was for guests who urgently needed to leave and to bring in supplies.

She said the town had not seen so much snow for several years.

“It surprised us a bit this year and we’re trying to make the best of it,” Ms Biner said.

An avalanche crosses the road and railway on the way towards Zermatt in St. Niklaus (Dominic Steinmann/Keystone via AP)
An avalanche crosses the road and railway on the way towards Zermatt in St. Niklaus (Dominic Steinmann/Keystone via AP)

Switzerland’s WSL Institute for Snow and Avalanche Research said at least 31.5in of snow had dropped on the Zermatt area over 24 hours, raising the risk to a maximum level of five on an avalanche-warning scale.

The snowfall in the Zermatt and Saas valleys was part of a broader weather pattern that was causing mudslides and intensifying the avalanche risk across a broad stretch of south-western Switzerland.

In some more remote areas, the snowfall topped 39in over 24 hours, the institute said.

The WSL Institute pointed to “mid-range and large spontaneous avalanches” in the area with the risk of more avalanches increasing.

It said the snowpack below 6,500ft had been weakened by heavy rain.

Authorities said conditions are expected to improve on Wednesday.