A "mega blaze" raging across a 60km front north of the Australian city of Sydney cannot currently be put out.
The blaze across 300,000 hectares is just an hour's drive from the nation's most populous city.
BBC News reports people who cannot defend their property from approaching fires have been told they should leave immediately.
Since October, bushfires have killed six people and destroyed more than 700 homes across Australia.
The severity of the blazes so early in the fire season has caused alarm, and prompted calls for greater action to tackle climate change.
Fires have also raged across Queensland, Victoria, South Australia, Western Australia and Tasmania.
