Bushfire spreads in WA Swan district

An out-of-control bushfire continues to spread in WA's Swan district.

An emergency fire warning is in place for the northwestern part of Bullsbrook, and the blaze is moving at 2.2km/h in a northwesterly direction.

The warning covers an area bound by Wanneroo Road, Old Yanchep Road, Tomar Road, Cypress Road, Wandoo Road, Neaves Road and Joondalup Drive.

The Department of Fire and Emergency Services says the fire is "out of control and unpredictable".

Residents have been told to leave if the way is clear but to stay put and defend their homes if it is not.

A watch and act has been issued for north of Tomar Road and up to Pigeon Road. A watch and act alert remains for people near Gully Road, Robinson Road, Payne Road, Raphael Road, Cooper Road, Rae Road, Strachan Road, Old West Road, Davidson Street and Stock West Road.

The same threat level is in place for Butler, Ridgewood, Merriwa and Quinns Rock in an area bound by Old Yanchep Road, Wanneroo Road, Pipidinny Road, Hester Road and the coastline.

"You are in danger and need to act immediately to survive. There is a threat to lives and homes," the fire service said in a statement on Saturday.

The fire started between Railway Parade and Gully Road and jumped over Perry Road and is now burning in Gnangara Pine Plantation towards Wanneroo Road.

The blaze is expected to reach Old Yanchep Road at 7pm.

More than 1000 hectares have been burnt and about 200 firefighters are battling the blaze.

It is not known how the fire started.

Evacuation centres have been set up at Wanneroo Recreation Centre and Gum Blossom Hall in Quinns Rock.

There were reports of three homes on fire in Pinjar in Perth's northern suburbs.

A fire service spokeswoman said she was unable to confirm this.

Photos posted on social media showed huge thick plumes of smoke looming low over rows of bungalows.