Fires burned in Los Angeles County, to the east in Riverside and Orange counties, and to the northwest in Santa Barbara County. More than 800 houses, mobile homes and apartments were destroyed by fires that have burned areas more than 34 square miles since breaking out Thursday.

"This has been a very tough few days for the people of Southern California," Gov. Arnold Schwarzenegger said after touring damage.

The smell of smoke pervaded metropolitan Los Angeles. Downtown skyscrapers were silhouettes in an opaque sky, and concerns about air quality forced organizers to cancel a marathon in suburban Pasadena where 8,000 runners had planned to participate.

Fierce Santa Ana winds that fanned the fires on Saturday weakened Sunday morning, allowing firefighters to set backfires to prevent flames from advancing to hillside neighborhoods. Air tankers swooped low over suburbs, red fire retardant billowing from their bellies as they painted defensive lines between brushlands and homes. Big helicopters shuttled back and forth on water drops.

The most threatening blaze had scorched more than 16 square miles in Orange and Riverside counties after erupting Saturday and shooting through subdivisions entwined with wilderness parklands. By midday Sunday, multimillion-dollar homes were being threatened in Diamond Bar in Los Angeles County as the out-of-control fire pushed northward.

Fire officials ordered 1,400 more residents to evacuate Sunday morning. Gov. Arnold Schwarzenegger said 26,500 people remained under evacuation orders for that fire alone.