A series of avalanches in Austria has left three people dead since Friday, as the ski season gets into full swing, with authorities warning of the risks posed by a particularly unstable snow cover.

"One winter sports enthusiast was killed in an avalanche in Kaltenbach on Saturday," a police spokesman told AFP, declining to give any information about the circumstances of the accident in the small Alpine village.

According to the Austrian news agency APA, the victim was a 17-year-old New Zealander who was skiing off-piste.

On Friday, a 32-year-old Chinese man, also said to be skiing away from the designated routes, died in an avalanche in the resort of Soelden.

A third victim was found dead Saturday after being reported missing the previous day.

APA reported that the man was 50 years old and died in the Kleinwalsertal valley on the border with Germany.

Over the past two days, intensive snowfall and wind have increased the avalanche danger in the Alpine Tyrol and Vorarlberg regions.

Warnings have been issued in  both these popular ski resort regions, urging winter sports enthusiasts to exercise caution.

However an alert level four, on a scale of five, has not prevented many holidaymakers from venturing off the marked slopes, authorities said.

The avalanche situation also led to numerous rescue operations on Saturday, made hazardous by the weather conditions.

The February school holidays have begun in Vienna and resorts have filled up, after a gloomy start to the season, marked by the absence of snow at low and medium altitudes.

In recent years, in Austria, a leading winter sports destination, there have been an annual average of 20 deaths on the slopes.