SYDNEY, Aug. 9 (Xinhua) -- Australia's southeastern states have endured severe and destructive weather as an icy Antarctic vortex brought heavy winds, rain and snowfall, as well as an increased risk of avalanche for alpine regions.

"A deep cold front formed to the south of Australia over the Great Australian Bight and over the last 24 hours it's moved over Bass Strait bringing with it some damaging to locally destructive winds for parts of (Australian States) South Australia and Victoria," Bureau of Meteorology Severe Weather Meteorologist Diana Eadie said.

"With these windy conditions and this heavy snowfall, there's an increased risk of blizzard activity as well as the risk of some localized avalanche activity."

Wind gusts of up to 94 km/h across Victoria's capital city of Melbourne have seen a number of cars crushed by trees, including one incident which left a child critically injured.

Earlier, residents in Melbourne's South East watched on as a large pier broke away from its foundations and floated free in the surf, travelling hundreds of meters across the bay, propelled by wind gusts of up to 110 km/h.

Airports in the east of the country have warned of delays and advised passengers to check with their airline for updates.

More than 75 domestic flights out of Sydney airport were cancelled on Friday morning, with only one runway operating. Delays were expected to continue for both domestic and international flights.

Meanwhile, Melbourne Airport saw 23 domestic flights cancelled, although international services were not impacted.

Eadie said the conditions were expected to continue across the weekend, with some areas worsening before the winds begin to ease early next week.

"We're expecting a continuation of these wet, windy and cool conditions with a secondary front moving over southeastern Australia over the next 24 hours," she said.