Authorities have confirmed an out-of-control bushfire burning near Nanga Brook was not deliberately lit.
The fire, which started on Saturday afternoon near the Nanga townsite, has burnt through over 3000 hectares.
An emergency warning remains for people in parts of Blythewood, Coolup, Meelon, Nanga Brook, Oakley, Teesdale and Waroona.
Fire and Emergency Services Commissioner Darren Klemm said firefighters made good progress overnight.
"They were successful in containing the northern flank through backburning, however they are still facing variable winds and difficult terrain on the western side today," he said.
"The fire is burning through steep and hilly terrain with thick forest and old growth pine that is very dry and difficult to access.
"Crews are working to build containment lines around the 50 kilometre perimeter of the fire."
Commissioner Klemm confirmed two outbuildings have been destroyed and they are expecting further property loss.
"DFES’s Urban Search and Rescue Team are back on the fireground this morning and are conducting Rapid Damage Assessments. They had to stop work yesterday because of the danger of falling trees," he said.
Commissioner Klemm said the cause has been deemed as accidental.
"The cause of the fire is accidental and is believed to be due to campers using a car battery to charge devices," he said.
A community meeting with be held at 2pm on Monday at the Murray Aquatic and Recreation Centre in Pinjarra.
The meeting will be livestreamed via the Shire of Murray Facebook page.
Keep up with the latest bushfire information at Emergency WA.
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