California fires: Death toll climbs to 40 as emergency workers struggle to control more than a dozen blazes

California governor Jerry Brown called the tragedy ‘a horror that no one could have imagined’

Firefighters work to defend homes from an approaching wildfire in Sonoma, California (REUTERS)

Firefighters are still battling more than a dozen fierce blazes that are raging across northern California as the death toll soared to more than 40 and is expected to rise further amid the crisis.

Powerful shifting winds have left emergency service workers struggling to control the wildfires, while low humidity has dried up vegetation and turned vast areas into a tinderbox, officials said.

The number who lost their lives climbed over the weekend as massive flames engulfed built-up areas, forcing thousands to flee in one of the worst outbreaks seen in the state.

More than 10,000 firefighters and police have been deployed in a massive emergency operation where more than 100,000 people have been evacuated from their homes, with hundreds unaccounted for.

The numbers rushed out of their properties included 3,000 in the city of Santa Rosa, which lies just about 50 miles north of San Francisco.

California governor Jerry Brown, speaking in Santa Rosa in a crisis meeting with officials, said: “This is truly one of the greatest tragedies that California has ever faced. The devastation is just unbelievable." Quoted in a report in the LA Times, he added: "It is a horror that no one could have imagined.”

A total of 17 wildfires are raging across northern California. Fire crews overnight rushed to areas affected including in Sonoma County, Yuba County, Mendocino County and Napa County – where blazes engulfed neighbourhoods and claimed more lives.

Images in Napa County, where six died, showed whole streets reduced to charred debris. Rescue workers continue to pick through rubble in the search for further bodies in the tragedy.

Hillsides were left blackened and several wineries – the county’s main industry – were burned down to remnants, with nothing but brick frames and melted equipment left after the blaze.

The raging fire – dubbed ‘Atlas’ – has scorched more than 50,000 acres. Firefighters said it continues to threaten about 5,000 homes, but that they have contained almost half of it.

Twenty-two have lost their lives in Sonoma County where the Nuns fire has spread rapidly overnight, threatening the outskirts of the city of Sonoma and the Oakmont neighborhood in Santa Rosa. It was 10 per cent under control by yesterday, officials said.

High winds spread the fire across parts of the county – that was already devastated by the Tubbs fire earlier in the week – as police helped fire crews to evacuate the area.

"I don't think I've ever seen that many cop cars," CalFire spokesman Jeff Allen told the LA Times.

Rescue workers in Mendocino County, where eight people have lost their lives, said they had the raging Redwood wildfire 20 per cent under control.

The Pocket wildfire burns in the hills above Geyserville, California, U.S (REUTERS)

Officials said dry weather meant the conditions were ripe for further outbreaks of blazes across northern California. Low humidity has left vast areas vulnerable to further fires.

“It’s been drying out the mountains,” National Weather Service forecaster Steve Anderson, according to a report in the LA Times. “It’s still going to be bone-dry out there overnight.”

In Sonoma county, a school headmaster summed up the fears that the blaze could get worse, according to a report in The Guardian.

He said: “In the afternoons we start looking up at the flag pole and we start looking to see, is the wind blowing? Is the flag moving?” he said. “It’s been really crazy.”