France is adopting new measures to stamp out anti-Semitism in schools, described as a "true danger" by the education minister.
Luc Ferry said anti-Semitic insults of a new kind were becoming a feature of everyday life.
Teachers and school officials would no longer be allowed to turn their heads when Jewish students were being harassed, he said.
Some 455 racist and anti-Semitic incidents were recorded in French state schools in the autumn term alone of the current academic year.
School officials say most of the incidents involve verbal insults and offensive graffiti.
Correspondents say attacks against Jews and synagogues have intensified in France since 11 September 2001.
And France's Jewish community - the largest in Europe - has accused the authorities of turning a blind eye to the rising anti-Semitism.
Tough line
French media recently reported that an 11-year-old Jewish boy in Paris was forced to change schools after being bullied by students of Arab origin.
Many teachers have also complained that teaching the Holocaust has become impossible in some classrooms because of hostility towards the subject by students of Arab origin.
Mr Ferry said that anti-Semitism was apparently more tolerated "because it is coming from a source supposedly more acceptable than the classic far-right, notably the Arab-Muslim world".
He said education officials had been told to take a tougher line against those engaged in anti-Semitic or racist behaviour.
Pupils involved in racist behaviour could face expulsion or even legal action, Mr Ferry warned.
Religious symbols
Mr Ferry also said that his ministry would set up an action and surveillance unit to help schools tackle the problem.
But he warned that "the imminence of a possible war on Iraq is not going to help matters".
If things got worse, he added, France could reassert the secular nature of the country's education system.
"In an explosive situation we should be able to say to all students: 'Drop the crosses, the veils, the skull caps, we are going to stop that and play by the rules of the republic'."
The wearing of religious symbols has proved controversial in the past in French state schools, with many girls being expelled for wearing headscarves during the late 1980s and 1990s.