Firefighters battled two suspicious house fires in Perth's suburbs overnight.
The first fire started in Rockingham about 12.50am and caused $100,000 damage to a two-storey home in Cygnus Street.
The blaze was attended by four fire crews and took about 50 minutes to bring under control.
A second suspicious fire caused $100,000 damage to a home in Whitehorse Drive, Burns Beach, after it started about 4am.
It took three fire crews about an hour to bring the blaze under control.
Police are investigating.