Erich Olson has begun carrying pepper spray — even on Shabbat.

He has also started covering his yarmulke with a baseball cap when he walks his dog.

Olson, 24, was attacked in the early evening near his Sacramento home last week by two men who first asked him if he supports Israel. Since then he has taken "extra precautions" he never imagined would be needed in his quiet neighborhood.

He is not alone. Throughout Northern California a marked rise in anti-Semitic incidents — including physical and verbal assaults on Jews, neo-Nazi graffiti and an arson attempt at a synagogue — has caused many in the Jewish community to think twice about their safety.

Their concern is not misplaced, according to Jonathan Bernstein, regional director of the Anti-Defamation League. Along with a surge in attacks on synagogues and Jews worldwide, he confirmed a "sudden and dramatic shift" in the local climate.

Since February, his office has received more than two dozen reports of incidents — three to four times the typical number and more than the total for last year.

"We don't anticipate it getting much better anytime soon," said Bernstein. "In the meantime, it's extremely important for the Jewish community to feel empowered. If we don't get out there and condemn [anti-Semitism] now, it will only fester and grow."

Among the reported incidents:

*An attempted firebombing of Temple Beth Israel-Judea in San Francisco.

*Anti-Semitic graffiti at Congregation Sha'ar Zahav in San Francisco, Temple Beth Jacob in Redwood City and Berkeley Hillel (which was also vandalized).

*Multiple physical assaults on Jews in Berkeley, San Francisco and Sacramento.

*An anti-Semitic blood-libel charge on posters at a San Francisco State University anti-Israel rally.

*Mezuzot stolen and graffiti appearing at an Israeli restaurant in San Francisco and on a dormitory door at U.C. Davis.

*Threatening phone messages like "stop massacring Arabs" and "God will punish you" at East Bay synagogues.

*Fliers claiming Israelis are murderers distributed at a Cupertino supermarket.

*Fliers blaming the Jews for the Sept. 11 terrorist attacks distributed by the National Alliance in San Jose.

Bernstein cited the ongoing war on terrorism as a primary cause for the outbreaks, which he said are more widespread in Northern California than in other U.S. communities, although a similar upsurge was also reported in Florida.

Following Sept. 11, he explained, rumors surfaced blaming U.S. support of Israel for the attacks, and Jews and Israelis worried about repercussions.

Instead, said Bernstein, the initial target was Arab-Americans, while the rumors about Israelis and Jews "were mostly rejected." However, with the escalation of Israel's response to terrorist attacks, particularly its West Bank military operations, many in Northern California seem to have found an excuse to vent anti-Semitic attitudes.

"In general, everyone out there is feeling very insecure — they're reminded of that insecurity every time they want to take a plane or go inside a tall building; even when they hear a loud noise," he said. "Unfortunately when people feel insecure, scapegoats give them comfort."

Olson, a member of both the Conservative Mosaic Law Congregation and the Orthodox Kenesset Israel Torah Center in Sacramento, learned that lesson the hard way. He was accosted while walking his dog on the evening of April 9.

Sacramento Sheriff's Department Sgt. James E. Lewis said two men, described as African-American, approached Olson and told him they didn't like Jewish people. They proceeded to punch and kick him, shouting "Jews kill innocent Palestinian children" and other anti-Semitic comments.

Detectives are investigating the incident as a hate crime, but they currently have no leads.

Olson, who suffered bruises and a sprained elbow, said he had heard "people shout things out their car windows at me" before, like "Jews suck" and "F—ing Jews." But it was "never anything as confrontational" as a physical assault.

Meanwhile, on area campuses like SFSU, U.C. Berkeley and Cupertino's De Anza College, Jewish students have reported that they "are no longer comfortable" wearing a Star of David or other Jewish symbols. They are afraid, said Karen Zatz, an associate director in ADL's Central Pacific office.

SFSU and U.C. Berkeley both have a large pro-Palestinian and pro-Israel presence. Campus representatives say the groups do not have violent clashes and the universities do their best to foster a tolerant environment.

But Bernstein noted that the ADL receives many reports of increased tension between the two groups, particularly during rallies. Last week fliers accusing Jews of eating "Palestinian children meat" were posted all over the SFSU campus and later condemned by the administration.

"It's a sad state of affairs," said Zatz, "that people can't feel comfortable publicly expressing" their Judaism on campus.

But even after finding gasoline cans and other flammable materials on his synagogue's roof March 22, Rabbi Evan Goodman of Temple Beth Jacob said he isn't afraid to express his Judaism publicly. Goodman said he also feels a "kinship" with other victims of hate attacks, including the primarily Arab-American congregation at the Antiochian Orthodox Church of the Redeemer in Los Altos Hills, which was destroyed last week by an unknown arsonist.

As for his own congregation, Goodman said, "We have turned to one another for support."

Bernstein supported Goodman's decision not to brush the incident under the rug and said it is "critically important" to report and address anti-Semitic incidents directly.

He also said Northern California civic and religious leaders must take more of a stand against hate "because it reminds the victim that they're not alone and it sets a positive tone" in the community. Leaders such as Berkeley Mayor Shirley Dean and SFSU President Robert A. Corrigan have issued statements condemning anti-Semitism, a move Bernstein called "encouraging."

The ADL is developing a public affairs campaign to target anti-Semitism in Northern California, recruiting celebrities, sports figures and community leaders to get out the message.

"You're never going to get rid of bigots," said Bernstein. "But speaking out against them will quickly change the climate in the community so that their ideas and hateful actions won't be embraced."

Meanwhile, the ADL and the Jewish Community Relations Council are planning a joint security briefing for Jewish institutions. Besides security issues, the meeting will address ways the Jewish community can overcome the growing climate of anti-Semitism.

For many Jews, these attacks are not only hate crimes but assaults on their faith.

When Olson returned home the night of his attack he immediately said evening prayers, "because I felt it was very important to thank God I was still alive." But before he could get through the Sh'ma, he broke into hysterics and called the police.

On the following Shabbat, when he stood on the bimah to say an aliyah, he saw his wife and began to cry. She was crying too. Olson never felt "prouder to be a Jew" and was thankful for the way that his community rallied around him.

"I'm not outraged that this happened to me," he explained. "I'm filled more with a deep sadness because you think that people are better than this."