A major emergency response is unfolding in Perth’s south due to a “serious incident”.

Significant police resources were sent to Keysbrook, about 73km south of Perth, on Saturday morning

One person has been arrested at the scene and is “assisting with inquiries”, a police spokesman said.

“There is no ongoing threat to public safety,” he said.

“The investigation remains ongoing.”

The nature of the incident is not yet known.

Members of the public are being told to stay away from the area and await further advice.

More to come.