A bushfire emergency warning was downgraded to an advice alert for people in Baldivis on Thursday evening.

The emergency warning was triggered about 9.30am near the intersection of the Kwinana Freeway and Safety Bay Road in Baldivis.

The fire from Flemington Drive, Baldivis.

Resident Ben Sturgess said ash was falling across the suburb following the blaze.

"Baldivis is in lockdown. There are cops everywhere," he said.