Police are investigating the cause of a bushfire in Secret Harbour.
The blaze started just after 1.30pm on Sunday in scrub near the intersection of Berryessa Parkway and Summerville Avenue.
Around 40 firefighters spent hours controlling the blaze, which caused the closure of Warnbro Sound Avenue.
A bushfire advice remains for the area.
The cause of the fire is not yet known, but anyone who saw any suspicious activity should contact Crime Stoppers on 1800 333 000.
Four hectares of land has been destroyed.