Sydney, Dec 7 (TIWN) Australian fire officials warned on Saturday that a mega bushfire raging across a 60 km front north-west of Sydney cannot currently be put out.

The fire across almost 300,000 hectares (1,150 sq miles) is an hour's drive from the nation's most-populous city.

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.