California camp fire triggers "mass devastation"

Thousands of residents are evacuating areas in Northern California as an uncontained wildfire race towards several towns in the Sierra foothills.

The Camp Fire, which started early on Thursday near Camp Creek, has been fuelled by strong winds and dry forest.

Neighborhoods, schools, and hospitals have been evacuated while some residents in the town of Paradise were trapped by the flames, officials say.

More than 2,200 firefighters are battling the flames and by late Thursday, the Camp Fire remains completely uncontained, according to the California Department of Forestry and Fire Protection (Cal Fire).

Authorities said there are unconfirmed reports of casualties.

"We have received reports of some fatalities," Butte County Sheriff Kory Honea told reporters. "Those reports have not yet been verified."

The Camp Fire has burned through 20,000 acres as of Thursday afternoon, local time, according to California Fire officials.

As winds approached 50 mph (80 km/h), causing the fire to grow rapidly in just a few hours, some residents were forced to abandon vehicles and escape on foot, local media reported.

Further south in Ventura County, north-east of Los Angeles, strong winds are preventing efforts to tackle another massive blaze - miles from the scene of a mass shooting in Thousands Oaks that claimed 12 lives on Wednesday.

The wildfire has spread from rural to populated areas, going from Pulga to Concow and destroying an unknown amount of homes in Paradise, a town of 26,000 people about 85 miles north of Sacramento.

The extent of the destruction is still unknown as firefighters have not been able to access Paradise to assess the damage, Butte County Fire Battalion Chief Bill Reid told reporters Thursday.

A red flag warning is in effect through Friday morning, meaning that firefighters face high winds and low humidity that help spread the wildfire. Authorities fear the fire, fueled by winds, would reach the city of Chico -- a city of 90,000 people where many Butte County families already have evacuated to shelters.

A shelter at the Neighborhood Church in Chico was full Thursday night and authorities were directing people to the Oroville Nazarene Church and the Butte County Fairgrounds.