A bushfire advice is in place for residents in the north-east part of Parmelia, in Perth's south.

Authorities say there is no longer an immediate threat to lives or homes, but residents are being urged to stay up to date on the situation.

Earlier, homes and lives were under threat in the area between the railway line, Challenger Avenue, Parmelia Avenue, Sulphur Road and Durrant Avenue.

Firefighters have managed to save several homes in the area since the blaze broke out, just after 1pm AWDT yesterday, but four homes have sustained minor damage.

At least 45 hectares of land has been burnt.

Ninety firefighters are on the scene and a team will remain there overnight.

Allen Gale from the Fire and Emergency Services Authority (FESA) says the fire is contained.

"The wind's not helping," he said.

"It's persistent, but it's not overly strong. It's a nice fresh breeze and I think that's what's caused a little bit of spotting going over the houses and up towards the railway line in the Sycamore Road area."

The authority has set up a relocation centre for residents at the Kwinana Aquatic Centre.

Challenger Avenue from Parmelia Avenue to Warner Road has been closed.

There is also an alert in place for all residents in the nearby suburb of Bertram for a fire that started on Johnson Road.

The FESA says both fires are suspicious.

Motorists are asked to avoid the area.