An emergency bushfire burning near homes south of Bunbury has been deemed suspicious by detectives.
Two fires were sparked on Saturday with firefighters being called out a blaze in Dalyellup at 2.20pm before another fire began in Usher at 4.20pm.
The two fires were brought under control by firefighters, however, the blaze in Dalyellup burnt through 120ha of bushland, coming close to the Dalyellup Beach Surf Life Saving Club.
In a post on social media, the club said its facility on Dalyellup Boulevard was safe but events had been cancelled because of road closures and smoke.
On Sunday, about 40 firefighters were strengthening containment lines but the fire was stationary and under control.
Multiple aerial support crews and around 80 career and volunteer firefighters were battling flames on Saturday night.
A police spokesperson said arson squad detectives were attending the scene today to investigate the cause of the blaze.
Detectives are calling for information as both fires are being treated as suspicious.
People in an area bounded by Killerby Drive to the north, Maidment Parade and Minninup Road to the east, Lakes Road to the south and the ocean to the west in Dalyellup were still on a bushfire advice level on Sunday morning, warned that while there is no immediate danger they need to be aware and keep up to date in case the situation changes.
Anyone with any information or who may have dash-cam vision is urged to contact Crime Stoppers on 1800 333 000 or online at www.crimestopperswa.com.au.