They were among a party of 11 ski hikers, believed to be French nationals, who were caught in an avalanche near Bourg-St-Pierre, said Jean-Marie Bornet, a spokesman for police in the Swiss canton of Valais.

Three people died and six people were injured, the Swiss news agency ATS reported, quoting police.

One person managed to escape the snowslide and raise the alarm, while nine others were found by rescue teams with tracker dogs rushed by helicopter to the mountainous area near the Italian border.

“We still have one missing,” Bornet told AFP.

“There were 11. It’s always a race against time.”

“Based on the first elements, they were French,” he added.

Bornet said the party was believed to be well equipped with avalanche detection devices and they were led by a mountain guide.

The area was on an alert level of three on a scale of five denoting a “marked danger” of avalanches on Saturday, according to the latest bulletin of the Swiss national avalanche centre.