High Desert Arson Spree Raises Fears : Fires: Investigators have been frustrated by a series of blazes near Lancaster.

An arsonist started a brush fire in the Antelope Valley hills on Tuesday, the latest in a weeklong spree of a dozen arson fires that has frustrated investigators and raised fears among residents in Los Angeles County’s fast-growing high desert region.

As in the previous fires, no homes were damaged or threatened Tuesday in the fast-moving blaze. But authorities said the toll could have been extensive if strong winds had not blown the fire east, away from the mountain communities of Lake Elizabeth and Leona Valley.

“If it had gone west toward the Leona Valley area we could have had some serious problems,” said Los Angeles County Sheriff’s Deputy Dan Watters, a member of the sheriff’s arson unit.

The fires generally have been confined to 10 square miles near Leona Valley and neighboring semirural communities west of Lancaster. They have come in clusters: two Monday night, four last Friday afternoon and another five last Thursday.

At least nine of the fires, the largest of which consumed 170 acres, appear to be the work of the same arsonist, authorities said.

In each of the fires, they said, the arsonist or arsonists have made stops on country roads, possibly while commuting between Lancaster and the Leona Valley, to ignite brush on the shoulder.

The blaze Tuesday began about 10:30 a.m. when a motorist pulled over on a barren stretch of road about 10 miles west of Lancaster, set a fire and sped away, officials said. Strong desert winds spread the flames through extremely dry brush, charring 70 acres before county firefighters could extinguish them.

The fires have been set in what is one of the hottest, driest and windiest portions of the county. About 10,000 people live in the Leona Valley and neighboring communities, and even in normal times brush fires are a major source of concern. The arson fires have heightened those fears, especially since they followed arson fires that claimed more than 500 houses in other parts of Southern California.

“It’s a very, very scary situation,” said community activist Gloria Gossard, who lives on a Leona Valley ranch. “There’s not a resident of Leona Valley who is not casting an eye skyward.”

Sheriff’s deputies have stepped up patrols for suspicious activity, and county firefighters have added extra manpower, officials said.

A Castaic man, 28-year-old David Wayne Cunningham, was arrested last Thursday in connection with three small fires that were set within a two-hour period. He initially reported two of those fires and claimed to have stomped them out.

He posted $10,000 bail that evening and will be arraigned later this month on arson charges.

Although Cunningham was still in custody when two more blazes were set, Watters said he has not ruled out the man as a suspect in subsequent fires.

Watters also asked for public assistance in finding a woman and two children who were seen near the latest arson fire Tuesday and might have witnessed it being set.

Investigators and residents suspect that the arson wave might have been inspired by major fires last week in Santa Barbara and Glendale.