Four cross-country skiers died in avalanches in the French Alps on the weekend, officials said as they warned of snow melting under springtime sun creating a heightened danger.

A 60-year-old man died on Saturday in the Haut-Alpes region.

The three others -- part of a group of five Frenchmen being guided up the Vanoise Mountain -- died Sunday in the Savoie region. Their companion and their guide survived and were hospitalised.

A rescue police commander, David Petitjean, said the avalanche Sunday happened in the morning so probably was not the result of the sun warming the surface snow.

But authorities in the Alps said there was a "strong" risk of avalanches in the wider area because of generally warmer weather.

A total of 32 people died during France's 2012-2013 ski season, according to the National Association for Snow and Avalanche Research.