Wildfires have destroyed at least 20 homes in Australia's Victoria state in what officials say are the worst fire conditions since a 2009 inferno killed 173 people.
Officials cited by the AFP news agency said on Monday that the fires were threatening the country's second-largest city, Melbourne.
"They were ferocious fires, they ran hard, they hit homes," Craig Lapsley, a fire commissioner, said.
The emergency comes almost exactly five years after the "Black Saturday" firestorm devastated the state, flattening whole towns. That inferno was Australia's deadliest natural disaster of the modern era.
"At this stage we have no evidence of loss of life which is a great effort by the firefighters and all emergency services, and at this stage we have no evidence of serious injury. That's first and foremost our priority - protection of life," said Dennis Napthine, Victoria state premier.
Fire crews said they saved about 550 properties from an intense blaze at suburban Keilor, near Melbourne's airport.
Fire fighting hampered
"It was very hard for us to initially get that fire to stop due to the fact that the winds were blowing up towards the airport," said Rob Purcell from the Metropolitan Fire Brigade.
Four blazes remained at emergency level on Monday including a 40km front on the outskirts of Melbourne, with
tens of thousands of hectares burnt.
Hundreds of people spent the night in shelters after being forced to flee their homes.
One man told the ABC that fast-moving flames had cut off his evacuation route, forcing him to stay and defend his property near Forbes, north of Melbourne.
"Amazing how fast it come up the gully and how big the fire front was. It was a massive wall of fire," said the man, who identified himself only as Peter.
The fire threat was expected to ease in many areas as cooler temperatures arrive from the south on Monday.
Vast wildfires are common in Australia's December-February summer months.