Paradise (California), Nov 9 (AP) Tens of thousands of people were ordered to evacuate a fast-moving wildfire that has exploded in size threatening several Northern California communities and forcing panicked residents to race to help neighbours who had to drive through walls of flames to escape.

It was not immediately known if there were injuries or fatalities.

Butte County Sheriff's spokesperson Miranda Bowersox said on Thursday that all of Paradise, a town of about 27,000 people 290 km northeast of San Francisco, was ordered to evacuate.

"It's bad," Butte County Sheriff Kory Honea told the Enterprise-Record.

"We're trying to get as many people out as quickly as possible and save as many lives as we can." Rick Carhart, a Cal Fire spokesman, said the wildfire affected about 30,000 people in the towns of Paradise, Concow and other small communities.

"The blaze is being driven by fairly strong winds," Carhart said. "It's really dry and we have low humidity and unfortunately those are great conditions for a fire to spread."

Thick grey smoke and ash filled the sky above Paradise and could be seen from miles away.

The Adventist Health Feather River Hospital in Paradise evacuated all its patients and staff, given its close proximity to the fire, and transported them safely to hospitals in neighbouring towns, said Jill Kinney, an Adventist Health spokeswoman. She said she did not know the exact number of people evacuated.

Four of the hospital's employees were briefly trapped in the basement and rescued by California Highway Patrol officers, Kinney said.

Enloe Medical Centre in nearby Chico received 24 patients, spokeswoman Jolene Francis said. Other patients were taken to Oroville Hospital in the city of Oroville.

Shary Bernacett said she and her husband tried to get people to leave the mobile home park they manage in Paradise and had minutes to evacuate as flames reached the east side of the town.

Bernacett said she and her husband "knocked on doors, yelled and screamed" to alert as many of the residents of 53 mobile homes and recreational vehicles as possible to leave.

"My husband tried his best to get everybody out. The whole hill's on fire. God help us!"" Bernacett said before breaking down crying.

She and her husband grabbed their dog, jumped in their pickup truck and drove through flames before getting to safety on Highway 99, she said. Carhart said officials were sending as many crews as they could gather.

"Every engine that we could put on the fire, is on the fire right now and more are coming," he said. "There are dozens of strike teams that we're bringing in from all parts of the state."

In Chico, west of the fire, resident Tina Greer said the care home where her disabled son lives with five other patients was evacuating. She said it takes time to pack the patient's medical equipment and medicine. Her 25-year-old son has cerebral palsy, needs a wheelchair to get around and is fed through a tube.

"They need time to prepare," she said. "There's a lot to move." Greer said heavy ash was falling in Chico.

The California Highway Patrol closed a nearby highway and urged motorists to avoid the area.

The National Weather Service issued red flag warnings for fire dangers in many areas of the state, saying low humidity and strong winds were expected to continue through Friday evening. (AP) NSD

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