The emergency warning area for an out-of-control bushfire threatening lives and homes south of Perth has been extended.

The warning area was extended on Sunday after “extreme unseasonal conditions” on Saturday.

The emergency warning is in place for people east of South Western Highway between Greenlands Road roundabout and Peel Road, bounded by Pinjarra Williams Road, Farley Road, Lane Poole Reserve, Murray River, Nanga Road, Nanga Brook Road and Peel Road, excluding the townsite of Waroona.

The warning includes the Meelon townsite and properties in the vicinity of Ridgeview Drive, and Nanga townsite in parts of Blythewood, Coolup, Meelon, Nanga Brook, Oakley, Teesdale and Waroona in the Waroona and Murray shires.

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“The fire is still spreading with strong winds in difficult-to-access steep and hilly terrain,” the Department of Fire and Emergency Services (DFES) said in an alert on Sunday.

“The fire ground is experiencing fresh and gusty winds this morning, decreasing into the evening.

“People in the area should remain vigilant in case the fire behaviour escalates again.”

Residents are being advised to leave for a safer place if the way is clear and if not, to be ready to shelter in their homes.

DFES said the fire, which started in state forest west of Nanga, had burned through 2477 hectares as of Sunday evening.

Authorities said the bushfire was unpredictable and moving fast in a westerly direction.

Aerial support has been sent to assist ground crews, with more than 250 career and volunteer fire and rescue service, bush fire service, volunteer fire and emergency services and Parks and Wildlife Service firefighters attending.

The Department of Communities has set up an evacuation centre at Murray Aquatic and Recreation Centre in Pinjarra.

Lane Poole Reserve and all campgrounds within the reserve have been closed.