Three skiers have been killed and a fourth remains in critical condition after an avalanche in the Swiss Alps.

The Italians had been cross-country skiing near the Grand Saint-Bernard pass, not far from the Italian border, when they were swept away around 1.40pm local time (12.40pm GMT).

They were among five skiers dug out alive after the avalanche but the three victims died later, police said.

Jean-Marie Bornet, a spokesman for regional police in the canton of Valais, has confirmed the deaths and revealed that one of the two survivors escaped with only minor injuries but the other was "undergoing resuscitation, so it's quite serious".

Police have not yet revealed the ages or genders of the victims.

Mr Bornet said the search for the skiers had been made more difficult by harsh weather, with heavy winds and thick fog forcing rescue helicopters to land further away from the avalanche site.

The Grand Saint-Bernard, at 2,459m high (8,100ft), is the lowest pass on the ridge between the Swiss Alps' two highest summits, Mont Blanc and Monte Rosa.