Perth bushfires: At least 10 homes lost as massive blazes see emergency warnings issued in six suburbs in city's north

A large bushfire in Perth's north that is believed to have razed homes continues to challenge firefighters, with an emergency warning issued for six suburbs.

Residents in Perth's northern suburbs have been forced to flee an out-of-control bushfire believed to have destroyed up to 10 homes amid scorching heatwave conditions.

West Australia's deputy premier Rita Saffioti confirmed in a press conference on Thursday that there had now been 'significant' damage from the fire that has now burnt through 1,663 hectares.

'I can confirm at this stage 10 homes have been lost, along with four sheds and numerous vehicles including caravans,' Ms Saffioti said.

'There's also damage to a range of infrastructure including power poles, but as this is a live emergency, it will take time to confirm the extent of the damage and the forecast for today is unforgiving.'

More than 100 firefighters are battling the massive blaze that forced hundreds of local families to evacuate their properties overnight as embers rained down on their homes.

Videos and photos posted online appear to show gutted homes and sheds with twisted and buckled tin rooves surrounded by blackened gardens.

Another recorded firefighters battling spot fires near homes in gusty winds and intense smoke that pushed the blaze into suburban streets.

An emergency warning remains in place for Wanneroo, Jandabup, Mariginiup, Melaleuca, Sinagra, Banksia Grove and Tapping, about 30km north of the city centre.

Some residents have been told it is too late to leave their homes and they should immediately find shelter away from the fire front that is moving in a southwesterly direction.

'You are in danger and need to act immediately to survive,' the Department of Fire and Emergency Services said on Thursday.

'There is a threat to lives and homes.'

Chief Superintendent Metropolitan David Gill says firefighters were working to strengthen containment lines around the blaze

'In these conditions, these fires can spread so fast,' he told ABC News.

He said the fire had 'pulled up' as it reached urban areas and was spreading on its flanks to the north and south.

'We are expecting strong winds again today in difficult conditions with high temperatures,' he said.

Western Australia is currently in the grips of a severe heatwave and Perth is forecast to reach 40C on Thursday, with wind gusts up to 80 km/h.

More than 1000 properties in the bushfire area are without power, with reports that power poles and lines and other infrastructure has been damaged.

Multiple evacuation centres have also been set up for residents and animals evacuated from the fire zone.

Local resident Bruno Rikli helped evacuate an elderly couple from home overnight as the firefront crept within a few streets of their property.

'There was a massive plume of smoke in the night sky and a ball of red embers that was glowing red,' he told AAP.

'Roads were blocked but we got them out.'

Mr Rikli said the couple's home survived the night without damage but the wind had started to whip up on Thursday morning, with ash falling on homes several kilometres west of the blaze.

'You can smell the smoke and it's hazy but fire crews are doing an amazing job,' he said.

The fire was reported about 1pm on Wednesday and 15 sq/km of bush and grassland has been burned.