A scrub fire in Bassendean last night required 40 firefighters and air support to bring under control.
The fire started just before 5pm near Seventh Avenue and Walter Road East.
A Department of Emergency Services spokesperson said the cause of the blaze had not been determined but signs pointed to a suspicious cause.
“There was no lightning or anything - it was possibly suspicious,” he said.
DFES deployed a helitac and water bomber because of the difficult terrain.
Career and volunteer firefighters from Kiara, Malaga, Belmont, Daglish, Canning Vale and West Swan took about an hour to bring the fire under control.
Crews mopped up the scene until just after 9.30pm.
No damage was reported and no homes were under threat from the fire.
A fireman was taken to Sir Charles Gairdner Hospital with leg injuries he received while fighting the fire.
Police and ambulance officers were also at the scene.
DFES personnel are expected to return to the site this morning to patrol the area.