Four dead and five others seriously injured after being trapped in the Swiss Alps

An unexpected storm in the Pigne d’Arolla area forced the hikers to spend the night outdoors

A helicopter flying over the Swiss Alps (File photo) (AFP/Getty)

Four climbers have died and another five are in a serious condition after they became trapped overnight on the Swiss Alps.

An unexpected storm in the Pigne d’Arolla area forced them to spend the night outdoors, police said.

They were apparently caught off guard by high winds and snow.

Police in Valais in south-western Switzerland said seven helicopters were used to rescue the 14 hikers who were from France, Germany and Italy.

Several of those rescued were suffering from hypothermia, with three dying in hospital. A fourth climber was reportedly killed in a fall.

They were taken by helicopter to hospitals in the area, the statement said.

A preliminary investigation found the victims were part of two groups of hikers and were crossing from Chamonix to the Swiss mountain resort of Zermatt on the 80km long Haute Route along the Italian border, according to Swissinfo.

Police said the group had been trying to reach the Vignettes hikers hut at 10,357ft (3,157m) when they were trapped by the storm.

Investigations continue.

Agencies contributed to this report.