Bushfire threat in WA's South West

Lives and homes could be in danger from an out-of-control and unpredictable bushfire burning in WA's South West region.

The Department of Fire and Emergency Services has issued a watch and act alert for people near Rocky Road, Rosa Glen Road and Warner Glen Road in Forest Grove, in the Shire of Margaret River.

The bushfire is moving fast in a southwesterly direction and burning embers are likely to be blown around homes, authorities warn, but the cause is not yet known.