THE Arson Squad are seeking witnesses to a bushfire that diverted ambulances away from St John of God Midland hospital last week.
The fire, reported just after 1pm on Friday March 2, burned 7ha of bushland just south of Clayton Street, Bellevue and north of Stirling Crescent, Hazelmere.
Ambulances were diverted away from St John of God hospital for about two hours during the afternoon.
A hospital spokeswoman said no patients were affected by the smoke while two staff members with a history of asthma were monitored.
About 70 career, volunteer fire and rescue service and bush fire service firefighters attended, supported by six aerial appliances including two helitacs and two water bombers.
The fire was under control at 4.15pm and contained at 5.38pm.
Department of Fire and Emergency services continued to monitor and patrol the area until Sunday evening.
The WA Police Arson Squad said three men wearing high visibility shirts seen close to the fire may be able to help police with their investigation.
They were in a vehicle described as a white dual cab truck with concreting equipment, including a cement mixer, on board.
Anyone with information regarding the fire, or who recognised the truck or men who were in the area, is asked to call Crime Stoppers on 1800 333 000 or report the information online at www.crimestopperswa.com.au
Rewards of up to $50,000 are available for information that leads to the identification and conviction of an arsonist.
By Claire Ottaviano