South Australia, WA towns battle bushfires

The residents of a small town in South Australia have been told to leave or take shelter from an out-of-control bushfire as residents south of Perth, in Western Australia, also battle a raging fire.

An emergency warning was issued on Saturday afternoon for Montacute, with a population of about 300, in the Adelaide Hills.

Fifteen tankers and eight aircraft are trying to contain the blaze, which is burning southeast toward the town.

Firefighters are contending with steep, inaccessible terrain in the Black Hill Conservation Park.

Residents are being told to take action as the bushfire could threaten their safety.

"Leave now. Check that the path is clear and go to a safer place," the SA Country Fire Service said.

"Do not enter this area as conditions are dangerous. Fire crews are responding but you should not expect a firefighter at your door."

Police have warned the uncontrolled fire could escalate with increased wind on Saturday afternoon.

"The Montacute fire is uncontrolled. This scrub fire is burning in both a southerly and easterly direction ... conditions are continually changing," police said in a statement.

Authorities have also advised about 22 residents in the nearby small village of Castambul to evacuate.

Meanwhile, in Western Australia, an emergency bushfire warning has been issued for parts of the Donnybrook-Balingup Shire in the southwest of the state - about 200km south of Perth.

Some 100 firefighters are on the scene working to extinguish the blaze.

Aerial support has also been dispatched.

The Department of Fire and Emergency Services said the bushfire was moving fast to the northwest and had already burnt 5095 hectares.

They said lightning had caused the fire.