An evacuation order has been issued for all of Lake Piru Recreation Area and east to the Los Angeles County line, south to SR 126, west to Center Street.

Firefighters Friday were trying to make progress after the Canyon fire exploded to nearly 5,000 acres, forcing residents in northern Los Angeles and Ventura counties to evacuate.

Andrew Dowd, the spokesman with the Ventura County Fire Department, said an estimated 150 to 200 firefighters were on the scene. “We’re doing a significant initial attack,” Mr. Dowd said.