Hundreds of police officers have joined in the manhunt for the suspected gunman in Monday's fatal shooting of a rabbi and three children at a Jewish school in the southern French city of Toulouse, as schools across the nation observed a moment of silence for the victims.

Interior Minister Claude Gueant told reporters Tuesday the identity of the gunman is still unknown, but said the person was likely wearing a small camera so he could record the rampage and post the images on the Internet.

“This element reinforces that psychological profile of the murderer that was established. All the witnesses have noted that he is someone very cold, determined, who has shown huge cruelty. The fact that he films his act to see them again or to broadcast them confirms this sentiment that this is someone particularly insensitive and determined.''

The suspect in Monday's shooting at the Ozar Hatorah school is also suspected in the murders of three French soldiers of North African and Caribbean origin in two separate attacks last week in Toulouse and the nearby town of Montauban. The killer escaped by motorbike in all the killings. The government has raised its terrorism alert to its highest level for the region around Toulouse, and security has been increased at Jewish and Muslim schools and houses of worship.

The dead included the rabbi's two young sons and the young daughter of the school's principal. The bodies of the four, who were dual French and Israeli citizens, are en route to Paris where they were to be flown to Israel late Tuesday for burial.

French President Nicolas Sarkozy led a moment of silence at a Paris school for the victims of Monday's shooting.

“These children were three, six and eight years old. The murderer hounded a little girl. It's a serious matter. So serious that the whole republic is concerned. Your teachers, your families and you.''

Mr. Sarkozy has suspended his re-election campaign until Wednesday.

France is home to at least a half-million Jews who represent Europe's largest Jewish community. The Toulouse shooting was the deadliest attack on that community since the early 1980s.

A French organization that monitors anti-Semitism says 389 incidents were recorded last year, ranging from vandalism to violence. The figure reported by the Protection Service for the Jewish Community (SPCJ) marked a decline from 466 anti-Semitic acts in 2010.

The Anti-Defamation League, a U.S.-based rights group, told VOA that Toulouse has seen several “troubling” anti-Semitic incidents in recent years, including the ramming of a burning car into the front of a synagogue while a rabbi and children were inside in 2009. Vandals broke into another local synagogue in 2010 and scrawled the words “dirty Jews.”

ADL's director of international affairs Michael Salberg said those incidents have left the French Jewish community feeling insecure. He said the response of French leaders and law enforcement to Monday's attack was “very positive,” but he said France must do more to prevent additional tragedies. Salberg urged French authorities to be on “constant alert for danger and to keep that level of vigilance high.”