People near Gracetown are being told to prepare to leave their homes as a bushfire burns fast and out of control in the South West region.

Picture by Showcase Photographix

The Department of Environment and Conservation has issued a watch and act alert for people in the area frmo Gracetown to Juniper Road and West of Caves Road.

The blaze started near the North Point carpark on Cowaramup Bay Road and is moving fast in a north-westerly direction.

Residents are being urged to evacuate or actively defend their homes.

Cowaramup Bay Road is closed from Gracetown east to Caves Road and motorists are being asked to avoid the area.

Firefighters, a helicopter and two fixed-wing water bombers are on the scene.

The cause of the fire is unknown.