A bushfire close to the Kwinana Freeway between the Karnup Road and Paganoni Road exits has reduced traffic southbound towards Mandurah to a single lane on Tuesday evening.
The Department of Fire and Emergency Services are working to extinguish the blaze, which was fire reported about 4.30pm and is moving slowly in an easterly direction.
While there is no threat to homes or lives, there is a lot of smoke in the area and the authorities have advised that the situation could change quickly.
Traffic is slow, with southbound traffic towards Mandurah reduced to one lane.
To keep up to date, visit www.emergency.wa.gov.au.