Violent storms lashed the Alpine country with rain this weekend, with hundreds of people evacuated in the west after the Rhone river and its tributaries broke their banks.

"The bodies of two people were found by rescuers in connection with the landslide in the Fontana region," police in the Italian-speaking canton of Ticino said in a statement.

According to local daily La Regione, the dead were two women who were on holiday in the region.

Emergency services were assessing the best way to evacuate 300 people who had arrived for a football tournament in Peccia, while almost 70 more were being evacuated from a holiday camp in the village of Mogno.

The poor weather was making rescue work particularly difficult, police had said earlier, with several valleys inaccessible and cut off from the electricity network.

The federal alert system also said part of the canton was without drinking water.

In the western canton of Valais, the civil security services said "several hundred" people were evacuated and roads closed after the Rhone overflowed in different locations.

Extreme rainfall also struck southeastern Switzerland last weekend, leaving one dead and causing major damage.