Wildfires raged out of control in western Australia on Wednesday, injuring three firefighters, destroying a number of homes and threatening several others.

The township of Toodyay, 80 kilometres northeast of Perth, the state capital of Western Australia, was evacuated Tuesday.

A fire there burned more than 2,700 hectares of forest and farmland by Wednesday and was still burning, the state's Fire and Emergency Services Authority said.

A second major fire remained out of control after burning 10,500 hectares near the village of Badgingarra, 160 kilometres north of Perth, the authority said.

Two firefighters were treated for smoke inhalation Tuesday and a third was treated for a heat-related illness.

Fire authority spokesman Allen Gale said the extent of the damage around Toodyay was still being assessed.

"We can confirm that 20 homes have been lost, but early indications of people moving through the area is that the number could double," Gale said.