Australind Police have urged the community to remain vigilant as the search continues for an arsonist they believe may be linked to four deliberately lit fires in the region.
Emergency Services personnel were called to a verge fire at the intersection of Dowdells Line and South Western Highway about 1.42pm on Monday, November 4.
The blaze travelled 300 metres before it was extinguished and was the fourth in a series of suspicious fires, all of which appear to have ignited from a grass tree.
Police confirmed that the fires, reported in Burekup, Waterloo and Dardanup, are believed to be linked to a single person.
Australind Police senior sergeant Mark Smith said one only had to look at the catastrophic fires gripping New South Wales and Queensland to see the devastating impact fire can have.
"That's what we're dealing with, that's potentially what could happen as a result of this," he said.
"It is pretty clear that someone has deliberately lit that fire.
"The circumstances could have been tragic.
"It's no secret that the ground is really dry and there is a bit of fuel around.
"For a fire like this to be deliberately lit is disappointing.
"Particularly when there is any kind of wind coming from the east, it could have been pushed right into those residential areas."
Sergeant Smith called on the community to remain vigilant and to report suspicious behaviour to police.
Under the Bush Fires Act 1954, lighting a bush fire carries a maximum penalty of 20 years in prison.
Australind Police would like to speak with anyone who was in the vicinity of South Western Highway and Dowdells Line about 1pm on November 4, or may have obtained dash cam footage, to contact Australind Police on 9797 0222.