A gunman on a motorcycle shot and killed three children and a rabbi at a Jewish school in the southwestern French city of Toulouse on Monday, according to a report from the Associated Press. 

A French police official says that the same gun was used to kill three paratroopers in two attacks last week, says AP. One of the attacks was in Toulouse, and the other was in Montauban, a nearby town, where two paratroopers were killed and another was seriously injured. 

The attacker's motives are unclear, but the possibility of a serial killer with racist motivations is concerning politicians, especially during this election year, the report says. The paratroopers killed were of North African and French Caribbean origin. 

French President Nicolas Sarkozy denounced "the savagery" of the attack and vowed to track down the killer or killers during a visit to the school. According to the report, Sarkozy ordered increased security at Jewish and Muslim buildings around Toulouse, and his prime misters told officials to "secure" all school and religious buildings across the country. 

The slain rabbi was 30-year-old Johnathan Sandler, who taught Yiddish at the school, according to another teacher, Uriel Torjmane. His 3-year-old and 6-year-old sons were among the children killed just before classes started at the Ozar Hatorah school, a junior high and high school. The 8-year-old daughter of the school's principal was also killed. A 17-year-old boy was seriously wounded and was in the operating ward of a city hospital at the time of the report. 

The gunman reportedly rode a dark-colored scooter or motorcycle to the scene and fired 15 shots into the crowd of children, teachers and parents. 

The attacker's methods are strikingly similar to the attacks on the paratroopers, and the caliber of bullet (11.43) is the same between all three shootings, the report says. 

France has the largest Jewish community in Western Europe, according to AP, estimated at about 500,000, as well as its largest Muslim population, about 5 million.

"It's a day of national tragedy," said Sarkozy. "The barbary, the savagery, the cruelty cannot win. Hate cannot win. The nation is much stronger."