Firefighters have slowed the spread of a huge wildfire churning through rugged mountains north of Los Angeles where dangerous winds gained strength again.

The fire threat remains critical in Southern California, where thousands of residents were under evacuation orders Wednesday as fire crews battled the out-of-control Hughes Fire near Castaic, a suburb in the foothills and mountains of northern Los Angeles County.

The blazes - named Laguna, Sepulveda, Gibbel, Gilman and Border 2 - flared up on Thursday in Los Angeles, San Diego, Ventura and Riverside.