"We are urging people to stay indoors and not to undertake unwanted journeys," a spokeswoman for New South Wales police told Reuters. "We expect the bad weather conditions to continue for some more time."

Police were searching for five people after their car was swept into a river when part of a highway they were travelling on collapsed on Friday afternoon.

The bodies of two people in their fifties were recovered earlier on Saturday. They were found inside their car which had been swept away by flood waters.

Strong winds and rains uprooted trees and caused flooding on some Sydney roads and around 200,000 residents were without power.

Local radio also reported minor disruptions to flights at Sydney airport.

Meanwhile, a beached cargo ship which threatened to break up causing a potential environmental disaster was still holding up, local media reported.

The "Pasha Bulker" had been anchored off the coal port of Newcastle on Australia's east coast awaiting entry when waves and gales swept it onto a reef and the local Nobbys Beach.

The storm has been whipped up by the worst low pressure system off Australia's east coast in 30 years, said met officials.