French President Nicolas Sarkozy and his Socialist opponent Francois Hollande have temporarily halted their election campaigns to visit the city of Toulouse where four people -- including three children and teacher -- have been killed in a shooting spree at a Jewish school.

Another teenage boy was seriously wounded in the attack.

French media reported that two of the murdered children belonged to the teacher who also died.

According to BBC, the gunmen fired shots at the Ozar Hatorah school while passing by on a scooter. The massacre has resulted in the entire city in the south of France on a “lockdown” as police search for the killer.

[The gunman] shot at everything he could see, children and adults, and some children were chased into the school, local prosecutor Michel Valet told French media.

The French paper Le Monde said Sarkozy will be accompanied to Toulouse by Education Minister Luc Chatel and Richard Prasquier, president of the Representative Council of Jewish Institutions in France (CRIF).

Whatever happens, faced with this kind of [death] toll, we can say that the French Republic as a whole has been hit by this appalling tragedy, the President told reporters.

Hollande said he will go to Toulouse to show his solidarity with the families and the Jewish community of France.

Gilles Bernheim, the chief rabbi of France, who is also journeying to Toulouse, said he was horrified and stunned by the killings. The Israeli government has asked French officials to shed full light on this tragedy and bring the perpetrators to justice.

Marine Le Pen, the extreme right-wing National Front candidate, also condemned the killings in a statement.

French police officials are concerned that the methods used in the murders are similar to the killings of three uniformed soldiers in two separate incidents last week in the same region of France (also by a man riding by on a scooter).

According La Depeche, the local newspaper in Toulouse, the killer at the Jewish school possessed two weapons, including a .45 caliber gun that was also used in the attack on soldiers last week in nearby Montauban.

However, Sarkozy cautioned it is premature to make a link between the incidents.