Nearly 140 bushfires are raging in the Australian state of New South Wales, with the most severe burning in Sydney.
At their peak on Thursday evening there were seven separate fires in different areas of the city. Firefighters battled them until the early hours of Friday morning local time.
Footage of one Sydney blaze shows firefighters running quickly away as the flames spread rapidly and suddenly.
Officials warned that many parts of the city would be blanketed with smoke.
At least four people have been killed and more than 400 homes have been destroyed since the fires broke out across Australia in early November.
Bushfires continue to rage in New South Wales, Victoria, South Australia and Queensland.
The fires are also worsening Sydney’s pollution problem. The NSW capital has already reached number 19 on the Air Visual global rankings of cities with the worst air pollution – putting it ahead of Shanghai and Mumbai.
Bushfires are common in Australia, but fire season this year has begun much earlier than usual – something meteorologists have said is exacerbated by climate change.
Temperatures have already exceeded 40C (104F), despite the southern summer not having started yet.