Fearing that the crisis in the Middle East could spill over into a wave of terrorism in Europe, Jewish communities and police across Europe are on their highest state of alert in a decade.
Already, scores of anti-Semitic incidents ranging from graffiti to street demonstrations to the firebombing of synagogues and Jewish businesses have been reported.
Jewish communities have heightened their own security, while governments and police have increased protection at Jewish institutions and other potential targets. "We must not relax our guard," a spokesman for a Jewish group told the London Jewish Chronicle, saying the threat was the most serious since the Gulf War in 1991 and the early days of the intifada in the late 1980s.
"What we have seen so far has been a mainly emotional response to what is happening in the Mideast," he said. "We are now entering a period where there could be more organized activity against us."
In the most recent incident, an Orthodox Jew is in serious but stable condition after being stabbed aboard a London bus Monday in an incident that the police are treating as racially motivated. A 27-year-old man "of Mediterranean appearance" is in custody, police said.
In the days between Rosh Hashanah and Yom Kippur, at least 50 incidents ranging from vandalism to anti-Semitic graffiti were reported at British synagogues. Militant Muslim demonstrators in London, Manchester and Birmingham burned Israeli flags, chanted slogans and distributed leaflets urging supporters to "kill Jews all over the world."
Nearly 100 anti-Semitic incidents were reported in France, including the fire-bombing of a Paris synagogue and a Jewish shop in Toulon on Sunday night, and similar attacks on several other synagogues and Jewish institutions, including at least one school.
President Jacques Chirac called the attacks "intolerable" and "unacceptable," and Justice Minister Lionel Jospin said police should crack down on "all acts and all attempted acts that are racist in character or anti-Semitic."
Henri Hajdenberg, president of CRIF, the umbrella body for French Jewish secular groups, blamed the attacks on extremist members of France's large population of North African Muslims.
France, with more than 600,000 Jews, and Britain, with 300,000, have the largest Jewish communities in Europe outside the former Soviet Union.
Germany has also seen a wave of attacks on Jewish sites in recent weeks.
The attacks began before the outbreak of violence in the Middle East, and most were attributed to neo-Nazi skinheads.
But just before Yom Kippur, a crowd of about 100 Palestinian and Lebanese demonstrators tried to storm the Old Synagogue in the city of Essen. The synagogue is a Jewish museum and Holocaust memorial center and is not used for worship.
Foreign Minister Joschka Fischer condemned the attack and said German authorities would not permit Jewish institutions in Germany to be targets of such violence.
In Italy, target of a number of bloody Arab terrorist attacks in the 1970s and 1980s, security was bolstered at synagogues, embassies, airports and Jewish and foreign schools.
Milan Police Chief Giovanni Finazzo said on Friday that U.S. and Israeli consulates were under 24-hour guard and that "other potential targets" would also be watched around the clock.
Clashes have been reported in Rome between young Jewish militants and right-wing extremists demonstrating in favor of Palestinians.
Italian Jewish leaders blasted what they said was one-sided media coverage that cast blame for the crisis on Israel and inflamed anti-Semitic feelings.
"The Italian mass media have started a disinformation campaign that nourishes anti-Israel and anti-Jewish hatred," Leone Paserman, the head of the Rome Jewish community, said in a statement.
He said he had "activated all channels at my disposal to signal the danger, both to the highest authorities of the policies and to the directors of information organs," he said.
In other incidents around the world:
Australian police are investigating two incidents in Sydney and Canberra, where gasoline bombs were thrown at Jewish targets during Sukkot. Also in Sydney, some 2,000 demonstrators marched on the U.S. Consulate, where they burned Israeli and American flags and set fire to posters of Israeli Prime Minister Ehud Barak.
Local Jewish leaders criticized South Africa's ruling party for organizing a Palestinian solidarity rally in Cape Town. The South Africa Jewish Board of Deputies plans to meet with officials from the African National Congress to discuss the ruling party's "behavior, or rather misbehavior," according to the board's national chairman, Russell Gaddin.
Argentine officials strengthened the police presence near Jewish and Arab institutions in response to the conflict in the Middle East. Security was also beefed up at the U.S. Embassy and at border crossings. In addition, Argentine President Fernando de la Rua convened the heads of the security forces and met with Jewish and Arab community leaders, who had written a joint statement calling for a cease-fire in the Gaza Strip and the West Bank.