A bushfire in Manjimup is out of control and unpredictable.
A watch and act has been issued for people travelling along the Muirs Highway south-east of Manjimup.
The bushfire is moving at medium speed in a south-westerly direction and has flames 4-5m high.
The blaze is burning in Dingup State Forest near Black Georges Road, in the locality of Middlesex, 10km south-east of Manjimup.
The fire is burning towards properties to the south-west in the Peppermint Grove Road area.
Firefighters are expecting the wind to change from the north-west to south-west.
A change in wind direction may push the fire towards properties in the north-east, the Muirs Highway and Black Georges Road area.
There is a possible threat to lives and homes as a fire is approaching the area and conditions are changing.
Department of Parks and Wildlife firefighters are at the scene supported by trucks and machinery.
The cause of the fire was reportedly roadside burning by private landowners.