PARIS — France may have chosen not to take part in the U.S.-led war against Iraq, but French Jews already are experiencing some of the war's effects.

With polls showing that more than 90 percent of the public is opposed to the war, major cities across France have been convulsed by large anti-war demonstrations that often have taken on a strong anti-American and anti-Israeli character.

The atmosphere exploded into violence last week when pro-Palestinian demonstrators attacked two Jewish youths outside the offices of the Hashomer Hatzair youth movement in Paris. The youths were taken to a nearby hospital and treated for light injuries.

Politicians issued belated, if forceful, condemnations of the incident. But French Jewish leaders are worried about further attacks — as well as the possibility that attempts by Jewish vigilantes to defend the community may devolve into street battles.

Earlier on the day of the Hashomer Hatzair attacks, Steve Soussan had been walking around Place de La Nation with his fiancee when he noticed a banner depicting the Israeli flag with a swastika at its center.

"I told them that 6 million Jews died in the Holocaust and they had no right to carry that banner. They told me that the flag represented the Zionist entity, so I tried to take it down myself," Soussan said. "Then they jumped on me and threw me to the ground and started kicking me."

Estimated at around 100,000 people, the demonstration was far from a minority affair.

Apart from the regular sprinkling of far-left and pro-Palestinian groups, representatives from some of France's mainstream political parties were present, including former Prime Minister Laurent Fabius, Green Party presidential candidate Noel Mamere and Socialist Party leader Francois Hollande.

Despite the fact that the Hashomer Hatzair attack was filmed by a camera crew, it took more than two full days for organizers of the demonstration to offer a clear condemnation.

Official responses were slow to emerge, and began to filter through only after Paris Mayor Bertrand Delanoe visited Hashomer Hatzair's offices.

A spokeswoman for the Green Party said she hadn't learned of the March 22 attack until two days later — not surprising, given sparse media coverage of the incident.

In fact, many papers carried an Agence France Presse dispatch claiming there had been "clashes" near the Hashomer Hatzair premises.

That raised the possibility that Jewish activists from Betar or the Jewish Defense League had clashed with members of the pro-Palestinian group Joint Appeal for Peace and Justice in the Middle East, known by its French acronym CAPJPO.

CAPJPO's president, Olivia Zemor, said Betar supporters had attacked activists from her group.

"We are going to be speaking to the police and asking for protection," Zemor said.

Asked how many people from CAPJPO had been injured in the alleged fracas, Zemor said she did not know the "exact figure." She then admitted that no one from her group had been hurt.