A wildfire burning in Southern California's Ventura County has grown to 9,700 acres.

The California Department of Forestry and Fire Protection said Wednesday the 15-square-mile blaze north of Moorpark is now 20 percent contained. It is expected to be fully surrounded by Saturday.

Two outbuildings have been destroyed but no homes have been damaged.

The fire erupted Tuesday as hot, dry and gusty Santa Ana winds swept into Southern California. A statement from the incident command team says the fire began in the area of a mulch pile and is under investigation.