Firefighters in Australia are bracing for a weekend of resurgent bushfires, with temperatures forecast to soar to 40 Celsius (104 Fahrenheit) in some areas.

Emergency teams made the most of a brief respite in the weather to construct fire breaks in the hope of keeping existing blazes under control.

We're looking down the barrel of another horror weekend Bob Debus, NSW minister

In Sydney, New South Wales State Premier Bob Carr cancelled a fireworks display to celebrate Australia Day on Sunday, saying such an event would be inappropriate.

Four people have been killed and more than 530 homes destroyed in fires which have swept across the country.

The most serious risk is to the Australian capital, Canberra, and the states of New South Wales and Victoria, where at least a dozen towns are under threat from the fires.

Fires have been burning in Victoria's high country and Snowy Mountains for weeks, and the deteriorating weather could aggravate the situation.

Bushfires have already destroyed some 260,000 hectares (650,000 acres) of national parkland in Victoria over the past couple of weeks.

'Horror weekend'

More than 60 fires are continuing to burn in New South Wales.

Huge swathes of land have been destroyed

The state's Emergency Services Minister, Bob Debus, warned of worse to come.

"We're looking down the barrel of another horror weekend with extreme weather conditions applying the blowtorch to bush that's dangerously dry because of the worst drought in 100 years," he said.

Firefighters are also continuing to battle blazes on the island state of Tasmania, where five homes were destroyed earlier this week.

In the northern state of Queensland, several homes were evacuated because of a fire about 300 kilometres (185 miles) north of the state capital, Brisbane.

In Canberra, emergency teams were trying to prevent a repeat of last Saturday's disaster when fires ravaged the city's western suburbs.

Fireworks cancelled

As the fires continued to burn, officials in New South Wales cancelled a spectacular fireworks display planned for Sunday.

"We're going to have a weekend where firefighters, thousands of them, will be deployed, risking their lives to save homes and farmland and farm animals," said state Premier Bob Carr.

"Out of respect for them and their efforts, their lives at risk and out of respect for people who might suffer the loss of property at the weekend, I don't think we can have a celebration based on fireworks," he said.

The bushfires were sparked by lightning and have so far caused damage estimated at A$150m ($87m).