Residents in the path of the bushfire raging in north-east Perth have been told it is too late to leave and they must make plans for how they would survive if flames took hold of their shelters.

The Woorooloo blaze had destroyed at least 71 properties by Wednesday morning.

WA’s Fire and Emergency Services Commissioner Darren Klemm said no properties were destroyed overnight, but assessment teams had confirmed the number of properties destroyed had risen to 71.

Authorities are still working through the fire zone.

He said they were concerned about high winds forecast for Wednesday afternoon, with wind gusts of 70km/h.

Mr Klemm said there were “challenging times ahead” and “still a long way to go with this fire”.

People in the Shady Hills estate, and on the outskirts of Bullsbrook, should have their bushfire plans in place.

Bushfire damage is real and devastating. Out Australian bush is drying through prolonged dry spells and increasing temperatures. This is the personal impact overnight in Perth, my home destroyed #ClimateCrisis #bushfires #perthfires pic.twitter.com/S6r09S3mQn

— ozexcon (@ozexcon) February 2, 2021

The expected wind shift could further complicate the task for crews who have battled the fire, which at times shot embers more than three kilometres ahead of the front.

The Bureau of Meteorology has predicted winds will swing south to south-easterly at up to 15-25km/h by midday (WA time) then increase to up to 40km/h in the afternoon.

There will also be little relief from the scorching heat for the more than 200 people fighting the bushfire, with temperatures remaining above 20 degrees in Perth overnight and expected to hit 34 in the city on Wednesday.

“You need to shelter in your home in a room away from the fire front and make sure you can easily escape,” the latest alert from Western Australia authorities reads.

“You must shelter before the fire arrives, as the extreme heat will kill you well before the flames reach you.

“If your home catches on fire and the conditions inside become unbearable, you need to get out and go to an area that has already been burnt.”

• To view which areas these alerts cover, click here

There is an emergency bushfire warning for parts of The Vines, Bailup, Ellenbrook, Gidgegannup, Millendon, Walyunga National Park, Upper Swan, Aveley, Henley Brook, Avon Valley National Park, Red Hill, Belhus, Baskerville, Herne Hill, Bullsbrook, Wooroloo, Brigadoon in the shires of Mundaring, Chittering and Northam, and the City of Swan.

A map of the path of the bushfire (in black) and areas included in the alerts.

Residents who are in lockdown areas or in self-isolation have been told they can defy coronavirus orders if their lives are in danger.

“You need to protect yourself and your family from the immediate danger of the bushfire first and foremost,” WA authorities said.

“Whether you are in lockdown or have been personally directed to quarantine for COVID-19, you must do whatever you need to do to keep yourself and your loved ones safe.”

People in areas where it has been deemed too late to leave should shelter in a room with two exits and water such as a kitchen or laundry.

The Perth Hills bushfire has burned through more than 1700 hectares of land. Photo: ABC

Some 2000 residents and businesses were left without power on Tuesday afternoon. About 150 poles and 100 transformers were down in the fire scar area, Western Power said.

The state’s electricity provider was unable to get into the fireground to repair damaged infrastructure and restore power. It was working with the state Department of Fire and Emergency Services to remove damaged power lines and poles.

Premier Mark McGowan said earlier on Tuesday that firefighters would continue to check destroyed homes in the rural suburb of Tilden Park to check if any lives had been lost.

He said a large aerial tanker was en route from NSW to help battle the blaze and the prime minister had been briefed on the situation.

“This is an extremely dangerous fire and a serious situation. Weather conditions are extremely volatile,” Mr McGowan said.

“Please do everything you can to keep you and your family safe and look after each other.”

-with AAP