Three men believed to be linked to Mohamed Merah were arrested in southern France.
French police searched the home of Abdelkader Merah, the brother of the man who murdered a rabbi and three children at a Toulouse Jewish school.
On March 19, Mohamed Merah, 23, attacked the Ozar HaTorah school in Toulouse in southern France, killing three students and a rabbi.
The European Jewish Congress (EJC) is demanding a more proactive response to the recent escalation in anti-Semitic attacks around Europe, which its leader called “smaller tremors before a massive earthquake.”
Toulouse killer Mohammed Merah visited Israel in late 2010, Israeli officials said.
The shootings of French soldiers and Jewish schoolchildren by a home-grown Islamist gunman killed by police have upended France's election campaign and resurrected conservative President Nicolas Sarkozy's prospects.
The standoff in France between police and Mohammed Merah, the suspect in the shooting at a Jewish school in Toulouse, stretched into its 13th hour Wednesday.