Raging fires stretching across Australia's east coast killed three people and destroyed more than 150 homes in Australia over the weekend. Senior firefighters warned yesterday the blaze could become so dangerous in coming days that they may be unable to protect lives and property.

From Crowdy Bay National Park on the coast of New South Wales state to just north of the affluent beach town of Noosa in adjacent Queensland state - a distance of 740km - emergency agencies were struggling to bring some 70 bush fires under control.

Eastern Australia's major north-south road, the Pacific Highway, was cut off by fire and smoke about five hours north of Sydney near the township of Johns River, where the body of a 63-year-old woman, Julie Fletcher, was found in her burned-out home.

Fletcher had messaged a neighbour that she had decided to abandon her house to the flames, which witnesses in the area said had become a wall 6m high that emitted smoke so thick it blotted out the sun.

Smoke haze from fires in the North East of #NSW are travelling across the Tasman Sea & over the Pacific Ocean. High to Very High fire danger in the North East of #NSW today. For the latest updates visit https://t.co/SPHgGeisGZ & #NSWRFS pic.twitter.com/rXIUdDGYd8

— Bureau of Meteorology, New South Wales (@BOM_NSW) November 9, 2019

"I got a message from her at 9.30pm on Friday night saying she was putting her things in the car and getting ready to go," Diny Khan told the Daily Telegraph. "She obviously never made it out. What a horrible way to go."

The two other victims died in the small town of Wytaliba near the Guy Fawkes River National Park, a reserve popular with bushwalkers and birdwatchers. A 69-year-old woman, Vivian Chaplain, died in hospital of severe burns after trying to protect her home, and a man, George Nole, was found inside a burned-out car, authorities said.

Satellite photographs showed smoke from the fires billowing hundreds of kilometres across the Pacific Ocean toward New Caledonia.

An estimated 350 koalas died when fire swept through their breeding ground near the coastal city of Port Macquarie. Koalas typically breed once a year, and it will be difficult for the population to recover, the president of the local koala hospital, Sue Ashton, told the Today television show. "I don't know how we are going to come back from this," she said.

On Tuesday temperatures are forecast to top 38C and winds of up to 35kmh will likely push the fires closer to the more-populated coast.

This shows the dangerous conditions that have confronted firefighters and residents today. This is the crew from Warringah HQ at the Hillville fire near Taree. #nswrfs #nswfires pic.twitter.com/lIhnF8P1Qf

— NSW RFS (@NSWRFS) November 8, 2019

Emergency services are so concerned that conditions are going to deteriorate over the next two days that they have warned people that they cannot rely on help and should consider evacuating in advance.

"Don't wait for the last minute and ring for a firetruck because it may not get there," deputy commissioner of New South Wales Fire and Rescue, Jeremy Fewtrell, said. "We just don't want to lose more people."

Firefighters are trying to predict where the existing fires will shift so they can deploy firetrucks and move people out before their lives are threatened.

"We're not out of this yet," Prime Minister Scott Morrison told reporters at a rural evacuation centre for fire victims yesterday. "There is a long way to go and Tuesday is looking more difficult."

All external fires have been banned in New South Wales state today and tomorrow, including wood barbecues, and bush fire conditions have officially been classified as "catastrophic" - the highest threat level - in the greater Sydney region for the first time.

Bush fires are responsible for more mass casualties in modern Australian history than any other natural disaster, and the penalty for breaching the fire ban is 12 months in jail.

‼️Sunshine Coast residents are being urged to remain vigilant as they return home after a tough couple of days.
Fallen trees, powerlines and debris can pose significant safety risks.
Keep up the great work everyone! 💪 pic.twitter.com/8X3VEYY3lo

— Qld Fire & Emergency (@QldFES) November 10, 2019

Many Australian environmentalists fear that bush fires are becoming more common because of global warming, and accuse Morrison's centre-right government of not doing enough to combat climate change.

As Australia's summers become longer and hotter, the dry countryside has become more susceptible to lightning strikes, lit cigarettes and other bush fire triggers.

During a briefing from firefighters yesterday, a protester yelled at the prime minister, "Climate change is real, can't you see?"

Asked if there is a link between bush fires and climate change, Morrison declined to answer directly. "I'm focused on the needs of the people in this room today," he said.

A local mayor, whose house was badly damaged in the fires, was more direct.

"It's climate change; there's no doubt about it," Glen Innes mayor Carol Sparks told the Australian Associated Press.