35 dead as California wildfires continue to rage

The wind-driven blazes, which erupted in the heart of California's renowned wine country, north of San Francisco, have destroyed an estimated 5,700 homes and businesses and forced the evacuation of at least 25,000 people.

With more than 200 people still missing on Friday in Sonoma County alone, and rubble from thousands of incinerated dwellings yet to be searched, authorities have said the number fatalities from the so-called North Bay fires would likely climb higher.

Even as firefighters gained more ground during a second day of better weather, they braced for a return of higher temperatures, lower humidity and strong, gusty winds that could increase the threat to communities still in harm's way.

Ground crews raced to clear drought-parched vegetation along the southern flanks of fires, removing highly combustible fuels adjacent to populated areas before extreme heat and winds were forecast to revive over the weekend.

"We've challenged the troops to get out there and secure mainly the south parts of these fires in preparation for those strong north winds," Bret Gouvea, deputy chief of the California Department of Forestry and Fire Protection (Cal Fire), told a news conference.

As of Friday afternoon, 17 major wildfires - some encompassing several smaller blazes merged together - had consumed nearly 222,000 acres of dry brush, grasslands and trees across eight counties.

Governor Jerry Brown planned to visit the area with California's two US senators on Saturday.

Officials have said power lines toppled by gale-force winds the first night may have sparked the conflagration, though the official cause remained under investigation.

Much of the devastation centered in and around the Sonoma County town of Santa Rosa, where whole neighborhoods were reduced to landscapes of gray ash, smoldering debris and burned-out vehicles.