LOS ANGELES (Reuters) - At least 220 homes were destroyed and four people reported killed by a series of massive wildfires that continued to scorch southern California on Sunday, and officials said there was no immediate end in sight as new fires popped up.

Fanned by the hot, dry Santa Ana winds and minimal humidity, major fires were raging in at least four places, having already burned more than 100,000 acres, threatened more than 30,000 homes across the region and caused millions of dollars of damage.

California Gov. Gray Davis declared a state of emergency in Ventura and San Bernardino counties, north and east of Los Angeles, respectively, and asked President Bush to declare a "major disaster" for both areas.

Though none of the fires were close to the city of Los Angeles, the smoke from some of the blazes was easily visible over the city just after sunrise, mixing with the early daylight and high clouds to create an unusual set of colors.

Regional air quality authorities issued an advisory for broad swaths of the region, warning of unhealthy air due to the smoke and urging people to limit outdoor activities. Residents of the Hollywood Hills, about 40 miles southeast of the Ventura County fires, said they could smell the smoke.

The weather outlook for Sunday was not favorable, with the National Weather Service forecasting temperatures in the high 80s and low 90s, with winds starting at 30 mph and gusting up to 60 mph.

"We've got weather conditions that we expect are going to continue like this in southern California into the middle of next week," Eric Lamoureux, a spokesman for the state office of emergency services, told Reuters.

He said the state has requested and received assistance grants from the Federal Emergency Management Agency to help defer some of the fire-fighting costs.

MANDATORY EVACUATIONS

Portions of major thoroughfares, including Interstate 15 and Interstate 210, were closed by the fires, and mandatory evacuations proceeded apace in communities east of Los Angeles like Glen Helen, Devore, Rialto, Claremont and La Verne.

One of the fires, known as the Grand Prix fire, was threatening power lines that supply about 25 percent of the Los Angeles basin's electricity.

That blaze was 23 percent contained as of Sunday morning, having already done more than $6 million in damage, according to the San Bernardino County Fire Department's Web site.

State officials did not have details on the two deaths, though local television said one person died evacuating from the fire area and another died watching a house burn. There were also reports Sunday of another two deaths at a new fire in San Diego.

Both the Grand Prix blaze and the "Old" fire, named for the Old Waterman Canyon where it started, were believed to be the work of arsonists, state fire officials said.

Pictures from local TV helicopters flying over the scene showed the fire "hopscotching," or jumping erratically from home to home, with some houses burned to the ground while others remained untouched.

A major fire was also burning uncontained near the Simi Valley region of Ventura County, and Lamoureux said two new fires had popped up in San Diego County. The widespread fires were stretching regional and statewide resources.