Australians are facing ‘off the scale’ fire risk and ‘catastrophic’ conditions from bushfires today, as flames burn out of control up the eastern coast.

People cut off by fire were told it is too late to evacuate and their best hope now is to take shelter.

Thousands of firefighters had spread out across New South Wales but were unable to prevent fires from breaching containment lines amid scorching temperatures and gale-force winds.

More than 100 bushfires are raging from Sydney to Brisbane, with eleven declared emergencies giving a direct threat to numerous towns.

Fire Service Commissioner Shane Fitzsimmons said: ‘Plenty of people have heeded the warnings and have left early.

‘Obviously, others have chosen not to.

‘Our advice to those who still may be there is that it is too late to leave on most of these fires, and sheltering is now your only option.’

Experts have described conditions as the worst on record, as spring temperatures climbed toward 40 degrees celsius and winds topped 50 miles per hour across a zone which has been plagued by persistent drought.

Even before unfavourable weather hit, days of fires had killed three people and destroyed at least 150 homes.

Strong west-to-east winds have spread existing blazes from dusty bushland to population centres nearer the coast.

Fitzsimmons said: ‘The conditions are expected to get worse.

‘Complacency kills.

A total ban on starting fires has been introduced while up to 600 schools are closed as well as many national parks.

The military have joined the firefighting, using more than 100 aircraft for water-dropping sorties.

New South Wales (NSW) state emergency services minister David Elliott said residents were facing what ‘could be the most dangerous bushfire week this nation has ever seen’.

Daniel Stevens is one of those who has decided to stay at home so far in the town of Hillville, where a fire which has already burned an area the size of 25,000 football fields is approaching.

Like many, his family – including his mother who has a broken leg – have packed their bags but have struggled over whether to leave their house and everything they own.

‘We’ll fight it first,’ he said, ‘but if it jumps the fence line into the paddock, we’ll go.’

New South Wales premier Gladys Berejiklian told reporters in Sydney: ‘The catastrophic weather conditions mean that things can change very quickly.

‘You might think you’re OK and a few minutes later you won’t be. Please heed all the messages you receive.

‘Tomorrow (Tuesday) is not the day to be complacent.’