Australian shares fell on Monday on heavy selling in insurer stocks after flash floods in the east coast caused massive damage to property and stoked expectations of increased claims, while losses among the mining sector also pressured the index.

The S&P/ASX 200 index was down 0.3% at 6,689.5 by 2315 GMT, and set to post its fourth consecutive session of losses. The benchmark closed 0.6% lower on Friday.

Heavy rains battered New South Wales over the weekend, causing the worst flooding in half a century in some areas, authorities said on Sunday, forcing thousands to evacuate and damaging hundreds of houses.

Insurers QBE Insurance, Suncorp and Insurance Australia slumped as much as 2.6%, 3.6% and 4.1%, respectively, after the flash flood spurred expectations of a surge in claims.

IAG said more than 2,100 claims had been lodged with the company by late Sunday covering mainly property damage, and that it was still too soon to predict the costs that would arise from the event.

Broader sentiment was also subdued after Wall Street posted a mixed performance in the previous session, as worries over the recent run-up in US Treasury yields persisted.

Mining stocks slumped as much as 1% to their lowest in seven weeks amid a drop in Chinese iron ore futures, with BHP Group and rival Rio Tinto losing as much as 0.9% and 1%, respectively.

Bucking the trend, Crown Resorts was the top performer in the index after the casino operator received an A$8.02 billion ($6.19 billion) buyout proposal from private equity company Blackstone Group.

Energy stocks also helped limit losses in the index, gaining 1.7% to be on track for their best session since March 12 on firmer oil prices.

Heavyweights Woodside Petroleum and Santos rose 1.7% and 1.3%, respectively.

In New Zealand, the benchmark S&P/NZX 50 index was dropped 0.5% 12,454.17, its lowest in a week.