TOULOUSE, France (AP) -- A motorcycle gunman opened fire 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 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 a.m. 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 caliber.

It was the latest in a week of motorcycle shooting attacks in France. A gunman on a motorbike opened fire on three uniformed paratroopers at a bank machine Thursday in Montauban in southern France, killing two and critically wounding the other. Four days earlier, a gunman on a motorbike shot and killed another paratrooper in Toulouse, about 50 kilometers (30 miles) away.

The Paris prosecutor's office said Monday it will investigate eventual terrorist links to Monday's killing and the two killings of paratroopers last week. The prosecutor's office, in a statement, did not indicate any evidence so far of any form of terrorism.

Both the prosecutor and Brandet said there were similarities with the attack four days ago in Montauban. Brandet noted that in both cases scooters were used and both suspects were apparently very determined.

A week ago in Toulouse, there was a deadly attack on another paratrooper.

In each case the assailant was on a scooter. Authorities said at the time that forensic analysis showed the same weapon was used in the shootings in Montauban and Toulouse.

President Nicolas Sarkozy accompanied by Richard Prasquier, the president of CRIF, the umbrella group representing Jewish organizations, were heading to the school.