France was plunged into mourning and national outrage Monday by the terrorist-style killings of three young children and a rabbi as they gathered for classes at a Jewish school in a quiet residential neighborhood of Toulouse.

The lone gunman rode up on a motor scooter and opened fire with two pistols, first shooting at a group of waiting children outside the school and then following some of them into a courtyard as they ran for safety toward the building, a local prosecutor, Michel Valet, told reporters. In addition to the four people killed, six students were wounded, including a 17-year-old boy reported to be in serious condition at a Toulouse hospital.

Those killed were a French-

Israeli rabbi sent to France to help teach in the school, and his two sons, 3 and 6, along with a girl who was the daughter of the principal. Her age was given variously as 8 and 10.

The style of the killings and one of the weapons used led law enforcement authorities to suggest a link with the slayings of three soldiers last week in the same area of southwestern France — and possibly a political motive arising from France’s military role in the Afghan war.

The first soldier was shot and killed in Toulouse on March 11 as he met a man who pretended to be interested in buying his motorcycle. Four days later, two other soldiers were killed and a third was badly wounded as they took money from an automated teller machine in Montauban, about 30 miles to the north.

Police said the same kind of weapon, a .45-caliber semiautomatic pistol of the kind once carried by U.S. armed forces, was used in all three incidents, including the one on Monday. Forensic tests later determined that it was the same pistol, according to the minister of the interior, Claude Gueant.

The evidence suggesting that a single killer was involved in all three crimes gave rise to the idea that the gunman may be a Muslim extremist driven by a desire to avenge French participation in the Afghan war, which could also be consistent with the attack on a Jewish school.

The issue was considered extremely sensitive in France during the presidential election campaign. Public opinion already has been aroused by a controversy over halal meat, or meat prepared according to Islamic tradition, and President Nicolas Sarkozy’s repeated promises to limit the number of foreigners — chiefly Muslims — who enter France illegally or are granted legal residence.

Against that background, Sarkozy traveled to Toulouse immediately after the shooting to show his concern. He was followed several hours later by Francois Hollande of the Socialist Party, his main opponent in the election this spring.

Sarkozy was accompanied by Richard Prasquier, president of the Representative Council of French Jewish Institutions.

“Today is a day of national tragedy. Everything must be put into action so the killer can be arrested and made to account for his crimes,” Sarkozy said. “It is not just the Jewish community that is concerned. It is the whole national community. On the territory of the republic, one does not assassinate children like this.”

Sarkozy decreed that all French schools observe a minute of silence Tuesday during which the young victims will be remembered.

Israel’s prime minister, Benjamin Netanyahu, expressed outrage that Israelis were gunned down in the street so far from home. “We are horrified by this attack and we are confident the French authorities will shed light on this drama and bring those responsible for these murders to justice,” he said in a statement released by Israel’s Foreign Ministry.

A spokesman for President Obama’s National Security Council, Tommy Vietor, expressed the U.S. government’s dismay at the news. “Our thoughts and prayers go out to the families and friends of the victims and we stand with a community in grief,” he said in a statement. “We join the government of France in condemning this unprovoked and outrageous act of violence in the strongest possible terms.”

The victims were standing on the sidewalk at a gathering point near the school, called Ozar Hatorah, in the La Roseraie residential neighborhood, when a man on a motor scooter, his head concealed by a helmet, drove up and opened fire with the two weapons, witnesses told reporters.

After he finished shooting, they said, he swiftly remounted his bike and sped away down the street. The scenario was almost exactly the same as those reported in last week’s killings of the soldiers.

Police cordoned off the area of the shooting and launched a manhunt involving what officials

described as an extraordinary force of thousands of officers

from several units, including

anti-terrorism specialists. The interior minister flew to Toulouse to personally take charge of the sweep.