A motorcycle gunman opened fire on Monday in front of a Jewish school in the southwest French city of Toulouse, killing a father, his two sons and one other child, the prosecutor's office said.

Prosecutor Michel Valet said a 30-year-old man and his 3-year-old and 6-year-old sons were killed in the attack just before classes started at the Ozar Hatorah school. He said another child, between 8 and 10 years old, was also killed, and a 17-year-old seriously injured.

French authorities were stepping up security at all Jewish schools in France, Interior Ministry spokesman Pierre-Henry Brandet said, adding the suspect made his getaway on a dark-colored scooter.

The school behind a high white wall with few external markings was cordoned off on Monday by police, who then escorted other children out. One officer held a distraught girl, her face in her hands. A mother and son wearing a yarmulke walked away from the site, their faces visibly pained. A video camera was visible at the school's entrance.

"The drama occurred a bit before 8 am. A man arrived in front of the school on a motorcycle or scooter," Valet said, adding that the man got off his scooter outside the school and opened fire.

"He shot at everything he had in front of him, children and adults," he said. "The children were chased inside the school."

The prosecutor said the suspect probably used two weapons, including one of a large calibre.

President Nicolas Sarkozy called the shootings an "abominable drama and a "frightening tragedy'.'

Sarkozy was heading to the site on Monday accompanied by Richard Prasquier, the president of CRIF, the umbrella group representing Jewish organizations, the president's office and CRIF said. The Education Minister Luc Chatel also accompanied the group.

Israel said it was "horrified" by the attack and a European rabbis' group denounced it as an "act of barbarity".

Parents of children at the school said a teacher and his two children were among the dead.

The prosecutor said that one person was seriously wounded in the attack, which came just days after two previous shootings in the region by a man on a motorbike who killed three soldiers.

So far there was no hard evidence of a link between the shootings, but Interior Minister Claude Gueant said that there were "similarities" and police said the same calibre weapon was used in all three attacks.

AP-AFP