Most of the city is now surrounded by the fires and dozens of suburban homes have already been engulfed by flames.
"
No area of Canberra is immune from this emergency, everyone should be filling their bath tubs with water in case of spot fires
"
Cameron Wade,
New South Wales fire service
High temperatures and strong, dry winds threaten to make the situation even worse.
Large areas of south-eastern Australia are being ravaged by the latest spate of fires, said to be the worst in 50 years.
Weather forecasters say more hot and windy conditions are on the way, and there are fears the nine separate fires currently ravaging the area could join together to form a giant unstoppable wall of flames.
Mass evacuation
Canberra is a city under siege, says BBC correspondent Phil Mercer.
One man has died after breathing in smoke while trying to defend his home - dozens more have been injured.
The emergency services cannot cope, our correspondent says, and many serious burns victims may have to be transferred to Sydney for treatment.
More than 2,000 people have been evacuated from the worst-affected regions, and troops are being deployed to help exhausted firefighters battle the blazes.
A thick blanket of black smoke hung over Canberra on Saturday, blocking out the sun.
In suburbs such as Duffy, fire provided the only light as the flames destroyed houses.
"I know mine's gone," resident Alan Latta said.
TALKING POINT
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I saw some flames that must have been 100 metres high
"
David, Canberra
"My mate's has gone. All my medals are lost. I've lost my wife and daughter and I can't find them anywhere."
Firefighter Peter Lucas-Smith, who was leading fire crews around Canberra, said: "You've really got to fall back and look at property protection, and the safety and welfare of your people and the community."
Tinderbox conditions
A spokesman for the New South Wales Rural Fire Brigade warned residents to take precautions in case fire swept into their own properties.
"No area of Canberra is immune from this emergency, everyone should be filling their bath tubs with water in case of spot fires," Cameron Wade told ABC radio.
While there had been some mass evacuations, officials urged people not to panic and said their homes might still be the safest place to be.
Strong northerly winds along with bone-dry conditions and high temperatures are, according to the authorities, making the situation worse by the hour.
Wildfires are common during the summer, but a year-long drought has made areas more vulnerable to serious outbreaks.
Mass destruction
The resort of Mount Hotham in Victoria has been evacuated after fires broke through containment lines.
Hundreds of holidaymakers and residents were forced to leave.
"
What [firefighters] are dealing with here is conditions we haven't seen for many decades
"
Phil Koperburg,
New South Wales fire commissioner
Vast swathes of land in the Snowy Mountains, south-west of Sydney, and the Kosciusko national park have been destroyed.
The New South Wales Fire Service commissioner, Phil Koperburg, said emergency workers had been pulled back from the front line in some areas because conditions were far too dangerous.
"What they are dealing with here is conditions we haven't seen for many decades," he said.
One official compared the situation to the serious outbreaks in 1983, when 76 people were killed in South Australia and Victoria.