THE Australian capital region has declared a state of emergency because of an out-of-control forest fire burning erratically to its south.

It is the first fire emergency for the Australian Capital Territory since 2003, when wildfires killed four people and destroyed almost 500 homes in a day.

The threat is posed by a blaze on Canberra’s southern fringe that has razed more than 53,000 acres since it was sparked by heat from a military helicopter landing light on Monday, the Emergency Services Agency said.

“The state of emergency sets a clear expectation for our community that we need you to be vigilant,” emergency services minister Mick Gentleman said. “This is the worst bushfire season in the ACT since 2003.”

The fire is burning at emergency level – the highest on a three-tier scale of danger – and embers have created dangerous spot fires nearby, agency officials said.

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Residents of southern Canberra’s suburbs and surrounding villages have been advised to prepare to either protect their homes or evacuate.

Roads were blocked to the village of Tharwa on Friday because the fire posed too much danger for residents to evacuate or return to their homes.

The fire is the most dangerous of dozens in Australia’s drought-stricken south east.

Unprecedented fires across southern Australia have claimed at least 33 lives since September, destroyed more than 3000 homes and razed more than 26.2 million acres.

The danger is forecast to escalate across the south east in the ACT and the states of New South Wales and Victoria as summer temperatures rise over the weekend.