The Department of Fire and Emergency Services believe two bushfires in the South West overnight were deliberately lit.
The fires in Yallingup and Injidup both started just before 6.30pm on Saturday.
Both blazes reached an emergency warning with nearby residents urged to leave their homes.
Luckily, significant rainfall helped fire crews bring the blazes under control.
Bushfire advices remain in place.
Anyone with information, CCTV or dash cam footage should contact Crime Stoppers on 1800 333 000.