A young man suspected of having attacked a group of Jewish youths with a hammer and iron bar last week turned himself over to police Thursday but denied involvement in the assault near Lyon, a police source said.
The man, aged about 20, was one of five people in police custody as of Thursday evening as police continued investigating Saturday's attack. The victims -- aged 18, 23 and 24 and all wearing Jewish skullcaps -- were attacked as they were walking to a religious service at a Jewish school in the east-central city of Villeurbanne.
Police have said a group jostled and insulted the victims, then about 10 other assailants armed with hammers and bars joined in.
The main suspect denied having used a hammer, but authorities think he did, the source said.
Civil liberties groups and leading political figures including the French prime minister have condemned the attack.
The victims were recovering after being treated briefly in hospital. The new assault against Jews has revived fears in France's Jewish community that anti-Semitism is on the rise in the wake of the shooting that claimed the lives of four French Jews, including three children, in the city of Toulouse in March.
That attack, carried out by radical French Islamist Mohammed Merah, sent shockwaves through France, which is home to Western Europe's largest Jewish community, about 600,000 people.
After Saturday's incident, the CRIF, the representative body of French Jewish organizations, noted that the attack "was not an altercation between gangs, but a clear act of anti-Jewish violence".
It said incident was "far from being an isolated act" and "part of the shocking surge of anti-Semitic violence that has followed the deadly attack at the Ozar Hatorah school in Toulouse".
The Union of Jewish Students in France warned authorities of zones in which Jewish citizens are continually targets of anti-Semitic acts. And another group, the Service for the Protection of the Jewish Community (SPCJ), issued a report condemning "the explosion" of anti-Semitic acts in the country since Merah’s killings.
According to statistics cited in the report, which were provided by the Interior Ministry, 148 anti-Semitic incidents, of which 43 were violent, were reported between March 19 and April 30. That's more than twice as many as the 68 recorded for the same period in 2011.
Aside from the numbers, the SPCJ is expressing concern "some of the people committing the acts feel empathy for Mohammed Merah".
The group points to several incidents in schools, including students refusing to participate in a minute of silence in honour of the Jewish victims, as well as pro-Merah graffiti found in bars.
The recent rise in anti-Semitic incidents is reminiscent of a similar trend in 2009, the year of the Israeli military operation in the Gaza Strip . The number of anti-Semitic incidents then doubled to roughly 815 in 2009 before falling sharply in 2010, and then rising again in 2011.

EJP