More residents of Southern California were urged to leave their homes Sunday despite calming winds that allowed a major aerial attack on wildfires that have destroyed hundreds of homes and blanketed the region in smoke.

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.

No deaths have been reported, but police brought in trained dogs Sunday morning to search the rubble of a mobile home park where nearly 500 homes were destroyed. They didn't find any bodies after searching about a third of the homes.

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