FESA incident controller Bruce Jones said firefighting resources had been stretched to the limit, with fires also burning in Two Rocks and Hope Valley this morning. FESA investigators are now searching for the arsonist responsible, saying there is "no doubt" the fire was intentionally lit.

Northshore State Emergency Service and other surrounding SES units provided valuable assistance in supporting the fire fighters and the helitac operators. Northshore SES Deputy Local Manager Nick Elliott said "Northshore volunteers were on scene by about 8am on the Friday, initially located down on Mounts Bay Road as well as at the Control Point on Forrest Drive. During the day our primary duties involved transporting fire fighters from location to location, and providing food and water to those fire fighters in the field. Our Local Manager Jim Maclean took the role of Bush Fire Liaison Officer".

FESA spokesman Allen Gale said the arsonist had chosen the hottest of the day of the year to strike, and the worst possible wind conditions.

Det. Sgt David Gorton, from the police arson squad, said the fire was definitely the work of an arsonist, but only one ignition point had been identified to date, despite earlier reports of multiple fires.

Mr Gale said crews from metropolitan Fire and Rescue Services, the State Emergency Service, the Department of Environment and Conservation, Kings Park and volunteer bushfire brigades had rushed to the scene this morning.

The Department of Environment and Conservation brought in tankers to assist helitacs already battling the fire.

Very hot conditions and fresh and gusty north-easterly winds did not help firefighters.

Kings Park and Mounts Bay Road were closed to traffic as the fire raged. Residents in upmarket homes bordering the park had been strongly advised to leave their homes. Thick smoke plumes billowed out of the park and engulfed apartments situated across the road from Kings Park.

A local resident, Michael, said he awoke to the smell of smoke, and was concerned for his safety. He was confident his home would be safe.

About 9am, embers from the fire sparked a smaller blaze near the boatshed on Mounts Bay Road, close to the Cygne apartments. Later in the day further fires started adjacent to the river as embers flew across Mounts Bay Road igniting whatever was in their path.

After news reports suggested that the fire was under control, a significant flare-up at about 2pm threatened the Old Swan Brewery, which was subsequently evacuated. FESA spokesman Allen Gale said the fire had started in a small area of thick bushland near Forrest Road. "It was a significant flare up - it came all of a sudden" he said.

This fire reignited bushland between Forrest Avenue and Mounts Bay Road but was brought under control by the use of helitacs and two fire-fighting elevated platforms.

All entrances to the park, all roads within the park and Mounts Bay Road from Riverside Drive to Hackett Drive remained closed for most of the weekend. Some roads still remain closed in King's Park.

PHOTOS - See seperate "Kings Park Fire" gallery or click HERE.