POLICE are investigating a scrub fire that had residents on alert in Carramar on Thursday.
The blaze began about 3.45pm near Pinjar and Redheart roads, burning close to 50sqm of land on a bush block behind a home.
About 30 firefighters had it under control by 4.45pm.
It followed a blaze in nearby Sinagra, which began in bushland off Wanneroo Road near Church Street, about 12.45pm.
A Department of Fire and Emergency Services spokeswoman said a power pole was believed to have caused the fire, but a Western Power spokesman said the utility knew nothing about the incident.
About 50 firefighters were required to attend the blaze, which began on private property, with an all-clear given about 4pm.