Update, 7pm: People in Bindoon are being urged to leave their homes immediately as an out-of-control fire with flames 20 metres high rages in the area.
The Department of Fire and Emergency Services has issued an emergency warning for people in an area bounded by Mooliabeenee Road, Bindoon-Moora Road, Great Northern Highway, Ioppolo Road, Brand Highway and Cockram Road in parts of Bindoon, Upper Chittering, Mooliabeenee, Lennard Brook and Breera.
The bushfire has slowed from almost 3km/h ti 300m an hour but remains out of control and unpredictable, according to DFES.
The fire is burning 400m from Cockatoo Drive on the eastern flank and is moving in a north-easterly direction.
DFES says lives and homes are under threat, in particular homes in the vicinity of Teatree Road and Hart Drive.
People in the area are being urged to leave in southerly direction via Chittering Road. A relocation point has been set up at the Muchea Recreation Centre on Archibald Road.
"It is not safe to stay and actively defend, your best chance for survival is to leave now," DFES said.
The fire was reported at 10.59am and has burnt through 2100 hectares. The caused has not been determined.
Those outside the area have been told it is not safe to return.
About 150 firefighters, 13 aerial water bombers and the aircrane are battling the blaze. A grader which was being used to fight the fire broke down and was returned to Gingin undamaged.
Fire crews at the scene say conditions have eased but the blaze is still burning out of control and has not been contained.
The Bindoon Primary School bus was cancelled due to the fire. The Department of Education said all students had been picked up by their parents and were accounted for.
Teatree Road between Gray Road and Cockatoo Drive, Ioppolo Road between Great Northern Highway and Reserve Road, Great Northern Highway between Blue Plains Road and Gray Road and Gray Road between Great Northern Highway and Teatree Road have been closed.
A watch and act alert has also been issued for people east of the Great Northern Highway in Bindoon.
DFES says there is a possible threat to lives and homes as the fire is approaching the area and conditions are changing.
People are being advised to put their bushfire survival plans into action and have been warned of an ember attack ahead of the fire.