Anti-Semitic acts nationwide declined by 4 percent last year, but the number of incidents nearly doubled in Northern California, according to an Anti-Defamation League report released Wednesday.

Among the most alarming trends: Perpetrators are getting younger.

"We documented one incident in Sacramento where the perpetrator was 7 years old," said Jonathan Bernstein, director of the ADL Central Pacific region. "It goes to show it is never too early to begin with intervention."

Overall, reported acts of hate directed at Jews increased by 23 percent in the Golden State last year — with Northern California accounting for much of the rise.

Sixty-eight such incidents occurred in northern half of the state last year, compared to 35 in 1998.

In particular, attacks on synagogues escalated in Northern California. Only three incidents were reported in 1998. But in 1999, the numbers jumped to 13 — including the June arsons at three Sacramento-area synagogues.

A county-by-county breakdown reveals most of the acts in Northern California took place in San Francisco, where 15 were logged, followed by San Mateo County with 9. Alameda and Sacramento counties each had 8 reported incidents.

Altogether, the state logged 275 anti-Semitic acts last year. The report breaks down the incidents into acts of harassment and vandalism.

Incidents of harassment in the state rose from 142 in 1998 to 166 in 1999, according to the report. The vast majority — 157 — targeted individuals. Only 9 were directed at institutions.

Attacks by vandals also increased statewide, from 81 in 1998 to 109 in 1999.

The worst anti-Semitic act in the state last year took place in Southern California when a man opened fire at the North Valley Jewish Community Center near Los Angeles in August, wounding three children, a teen and an adult.

"In the West, many extremists appear to be dancing in a mosh pit of hatred, bumping up against violent and racist ideologies of different hate groups," the report claims.

The report cites Benjamin Matthew Williams and James Tyler Williams, who have been charged in the Sacramento arsons, as sterling examples of hate: "Law enforcement officials found literature from a number of different, and often conflicting, hate groups," it states.

It also notes that hate groups once at ideological odds with each another have been joining forces against such "common enemies" as Jews, gays and ethnic minorities.

But Jessica Ravitz, ADL's associate regional director, said higher numbers in California may not mean a higher incidence of hate crimes. "I want to say people in California are more aware and are more likely to report things, but the truth is I'm not sure. The report is only as good as the reporting."

The 1999 audit counted 1,547 incidents in 41 states and the District of Columbia — the lowest number recorded since 1989.

Those included 868 acts of harassment, down 3 percent from the previous year, and 679 acts of vandalism, a decrease of 5 percent. Acts of harassment outnumbered acts of vandalism — a trend that has remained consistent over the past nine years.

In addition to California, New York and Massachusetts also showed increases.

Bernstein said the report reveals at least one positive trend: a drop in college-campus incidents.

The report documented only 60 incidents on college campuses, the lowest number reported since 1989 and a 30 percent dip from the previous year.

The report also takes note of trends that may portend greater trouble. Among them:

*The use of campus newspapers as a forum for Holocaust denial. Ads, opinion pieces and inserts, mainly from Bradley Smith and the "Committee for Open Debate of the Holocaust," based in Visalia, Calif., appeared in 19 publications nationwide.

*Leafleting at schools, churches, synagogues and parking lots by the National Alliance and the World Church of the Creator.

*Online hate, including exhortations to action and threatening e-mails. The Internet as a forum for anti-Semitism has eluded systematic tracking.

Skinheads who firebombed the San Jose home of a Santa Clara County Superior Court judge last summer accessed information from hate groups on their high school computers, Bernstein said.

"Hate on the Internet has really proliferated and has been linked to many acts of violence," he added. "People get the sense that if they act out on their prejudices there is a big audience out there that will applaud them."

According to Bernstein, the report can be a useful tool in sizing up where the greatest need lies and in brainstorming creative solutions.

"We must embrace the victims, mobilize community condemnation, push for strong law enforcement and legal responses, and, most importantly, teach our younger generations about the value of diversity," he said.