DFES has advised residents living in southern areas of Forrestdale to be vigilant as a bushfire continues to threaten residents.
DFES spokesman Allen Gale said the fire had been fanned by wind and has since doubled in size, remaining uncontained.
He said the fire had “jumped over Armadale Road”, while a watch and act alert had been extended to Harrisdale, with Piara Waters and Banjup under an alert.
“Firefighters have certainly been focusing their efforts thought not far from where it started,” Mr Gale said.
“It spread quite quickly.”
The fire began just after midday and was relatively close to homes.
The flames placed homes and lives under threat but so far there has been minimal damage to property.
Mr Gale said the resources were in full force to battle the blaze.
“Firefighters along with the helicopters, we had our water bombers, both the fixed wing and rotary wing working tirelessly there for a couple of hours just to make sure that properties are protected,” he said.
He added that it was not known what sparked the fire, but said last night’s storms remained a possibility.
Mr Gale said that resident should only defend their homes if they were prepared and advised people to leave their properties.
“If you haven’t got any plans in place and you don’t think you’re adequately prepared, then leave nice and early, find another place to go,” he said.