A fast-moving wildfire in the United States has destroyed hundreds of homes and other structures in the northern California village of Middletown and several nearby communities, according to fire officials.

California Governor Jerry Brown on Sunday declared a state of emergency in areas ravaged by the so-called Valley Fire, which has been ranked as the most destructive among dozens of blazes that have hit across the drought-stricken state this summer.

The blaze has consumed some 50,000 acres since it started on Saturday afternoon in rural Lake County, California, fire officials said on Sunday.

Maddie Ross, 25, a student who fled with her grandparents from their home, said “We were surrounded by fire.”

“It looked like hell everywhere,” Ross told the New York Times. “It was terrifying, truly terrifying. I’ve never been in a situation like that. We all felt like the world was coming to an end.”

Authorities also declared mandatory evacuation orders for communities in the vicinity of the raging fire. Middletown was one of the worst affected areas with almost all of its homes and businesses destroyed by the fast spreading fire. There's no official tally of the destruction yet.

"While crews have not had a chance to do a full damage assessment ... we know 100s of structures have been destroyed," said Daniel Berlant, a spokesman for the California Department of Forestry and Fire Protection.

"This has been a very destructive fire. It has destroyed countless homes and other buildings," he said in a video message to reporters. "Evacuations are widespread in the area."

"Every time they made progress, the fire would burn right past them," he added.

Several firefighters were reportedly injured with second-degree burns after they were dropped off by helicopter to battle the fire.

Meanwhile, more than 4,000 firefighters are battling another blaze southeast of Sacramento. These are the latest in a string of wildfires that have swept across the drought-stricken West Coast.