One man, aged 53, was crushed to death when a snow plough fell down steps in a "residential complex" in the northern city of Linz, police said.

Four skiers were killed in avalanches in the Tyrol region.

Three of them died in a giant avalanche near the St Anton ski resort, officials said. A German died on a slope at Nauders that was buried by snow. His 16-year-old son was seriously injured, officials added.

Tyrol authorities appealed for skiers to stay away from off-piste slopes as the latest deaths took to 21 the number of dead in avalanches in Austria this winter season. They said the risk would remain high for several days.

Up to 40 centimetres (16 inches) of snow fell on the Alpine nation since Thursday, prompting alerts for southeast Austria, notably in the region around the city of Graz.

Vienna airport temporarily closed in the morning, and afternoon services were "disrupted".

One of the main orbital highways around Vienna was closed for several hours, and other sections of highway were blocked by snowdrifts, stranded lorries or poor visibility, said the national automobile association, OAMTC.

Electric companies reported power outages in several regions in the south and east, including Styria, where 30,000 homes lost electricity.

In neighbouring Slovenia, 40,000 households were affected, according to local media, which reported major disruptions in the country's northeast.