SAN DIEGO - A man was charged with setting one of nearly a dozen fires that have destroyed homes and raced through nearly 20,000 acres (8,000 hectares) of brush land in northern and eastern San Diego County, but most of the blazes seemed to be dying down.

Thousands of firefighters and fleets of water-dropping military and civilian helicopters planned fresh battles against fires Saturday, including three fires at the Camp Pendleton Marine base.

Investigators continued to seek the causes of the conflagrations that burned at least eight homes and an 18-unit condominium complex, emptied neighborhoods and spread fields of flame, smoke and ash that dirtied the air in neighboring Orange County and as far north as Los Angeles County.

Alberto Serrato, 57, pleaded not guilty Friday to an arson charge in connection with one of the smaller fires, a 105-acre (42.5-hectare) fire in suburban Oceanside that started Wednesday and is fully contained.

Tanya Sierra, a spokeswoman for the San Diego County district attorney's office, said witnesses saw Serrato adding dead brush onto smoldering bushes, which flamed up. He has not been connected to any other fire, Sierra said.

Oceanside police Lt. Sean Marshand said Serrato is believed to have added fuel to the fire but not to have started it. ``Unfortunately we don't have the guy that we really want,'' he said.

Serrato remained jailed Friday, and Sierra said she didn't know whether he had an attorney.

All together, the wildfires about 30 miles (50 kilometers) north of San Diego have caused more than $20 million in damage.

Three fires continued to burn at Pendleton: A 15,000-acre (6,000-hectare) blaze that began Thursday was 40 percent contained, and a new fire Friday that quickly grew to 800 acres (320 hectares) was 25 percent surrounded that night. A 6,500-acre (2,630-hectare) fire that started Wednesday at a neighboring Navy weapons station and rolled onto the base and the city of Fallbrook was 65 percent contained.

At their peak, the fires prompted about 8,400 military personnel and their families to be sent home from various parts of the sprawling coastal base between Los Angeles and San Diego, but some housing-area evacuations were lifted, base spokesman Jeff Nyhart said.

The most destructive fires started in Carlsbad - a densely populated coastal suburb of 110,000 people where a badly burned body was found Thursday in a transient camp - and San Marcos, a neighboring suburb of 85,000 people where strip malls and large housing tracts mix with older homes whose residents cherish their large lots and country living.

The Cocos Fire, which hopscotched through San Marcos and neighboring Escondido, was 50 percent contained Friday night after burning 2,520 acres (1,020 hectares). The fire wasn't growing, and crews planned to keep mopping up hotspots, state fire Capt. Kendal Bortisser said.

An evacuation of the area was partially lifted, but some of those returning found disaster.

Dave Roberts' home in Escondido was gutted and its roof collapsed, although about 20 goats and some poultry he kept survived.

"My whole life is here and I lost everything,'' Roberts told KGTV-TV.

He built the home 20 years ago by hand. But he and his wife, Sherri, weren't giving in to disaster.

"Between my family and friends and relatives and everybody,'' he said in a choked voice. "I'll make it somehow.''

The region had become a tinder box in recent days because of conditions not normally seen until late summer _ extremely dry weather, 50-mph (80-kph) Santa Ana winds and temperatures in the 90s Fahrenheit (30s Celsius). On Friday, though, slightly cooler weather and calming winds aided the 2,600 firefighters, and thousands of people began returning home.

Six fires were entirely surrounded and several others were reduced to smoldering hotspots.

Eight of the San Diego County blazes popped up between late morning and sundown on Wednesday, raising suspicions that some had been set.

Police in Escondido arrested two people, ages 17 and 19, for investigation of arson in connection with two small fires that were extinguished within minutes. But they found no evidence linking the suspects to the 10 biggest wildfires.

The Bernardo fire, the first of the North County blazes to break out, burned 1,548 acres (626 hectares) and was 95 percent contained Friday night.

A backhoe operator at a development site accidentally started the fire while digging trenches, San Diego fire officials said Friday.