Strong winds, combined with an unusual heat wave for the season, have fueled bushfires in southeastern Australia, while authorities have issued an extreme fire risk warning for the greater Sydney region, home to more than 5 million people.

About 600 firefighters are battling to bring under control 68 bushfires that have broken out in the state of New South Wales, with 17 raging out of control, according to the latest official update.

Several parts of south-east Australia are being hit by a heat wave, which is not expected to subside until Wednesday, with the mercury climbing up to 16C above the September average.

The maximum temperature in Sydney exceeds 30 degrees Celsius for the fifth day in a row, which is unprecedented for this time of year. According to the meteorological service, from Thursday the mercury is expected to drop significantly.

Residents and tourists at a popular Tasmanian resort were told to move to a safer location on Tuesday as a wildfire raged out of control. More than 100 people were forced to spend the night in cars, according to Australian media.

Firefighters recently set up fire zones in Sydney’s west using controlled burning, as authorities fear this summer could be worse than 2019-2020. That “Black Summer”, as it was called, an area the size of Turkey had been reduced to ashes and 33 people had lost their lives due to the fires.