A sweeping manhunt is on in France after a motorbike-riding gunman left three children and a teacher dead at a Jewish school in Toulouse, southwestern France, on Monday. The shooting has been linked to two separate similar attacks last week in Toulouse and neighboring Montauban that saw three French paratroopers killed in cold blood in broad daylight—also by a gunman on a motorbike. Early reports suggest that the same .45-caliber weapon was used in all three attacks.

The French political class, from far left to far right, has unanimously condemned the latest incident, a month before France votes in the first round of its presidential election April 22. This sometimes ugly French election campaign has often shone a questionable spotlight on religious affairs and immigration. But on a day of shock and mourning in France, any fingerpointing is, for today at least, on hold.

Authorities say that just after 8 a.m., a gunman riding a scooter or motorcycle and wielding two weapons opened fire at close range on a group of adults and children in front of the Ozar Hatorah school on a narrow residential street in Toulouse. “He shot at everything there was in front of him, children and adults, and some children were followed inside the school,” Toulouse’s public prosecutor Michel Valet told reporters on the scene. Ozar Hatorah is a middle and high school, but younger children attending an elementary school nearby use the sidewalk outside as a meeting point. Some reports have given the adult victim’s name as Jonathan Sandler, 30, a Paris-born teacher who arrived from Jerusalem in September for a two-year teaching stint. Two of the dead children are Sandler’s sons, ages 6 and 3. The third child killed is the young daughter, believed to be 8 or 10 years old, of the school’s principal. A teenager, 17, seriously hurt, was undergoing surgery Monday afternoon in a Toulouse hospital. The attacker fled on his two-wheeler. French authorities are bolstering security across the country at religious establishments, particularly Jewish schools, as a manhunt involving a reported 150 investigators continues.

Indeed, French investigators were already on the trail of a scooter-riding gunman after incidents last week left three paratroopers dead and a fourth still fighting for his life in the hospital. On March 11, a French paratrooper was shot dead in broad daylight, at 4 p.m. on a Sunday, in Toulouse. The paratrooper had reportedly posted an advertisement online to sell his motorcycle; the gunman is thought to have posed as the potential buyer. Four days later, last Thursday, three more paratroopers were shot by a helmeted rider in cold blood as they withdrew cash from an ATM on a sunny street near their barracks in Montauban, 30 miles north of Toulouse. Two of the soldiers died on the scene. The third paratrooper was wounded in the spine and remains in critical condition in the hospital.

Investigators know from video surveillance footage that the Montauban shooter fled southbound toward Toulouse, using a route that suggests familiarity with the area. According to reports, they now know that the same large-caliber firearm was used in all three shooting incidents. And while the anti-Semitic inference is clear in the Jewish school killings, it has also been noted that all of the soldier victims were visible minorities. The soldier killed in Toulouse, Imad Ibn-Ziaten, 30, was of Moroccan origin. In Montauban, the two dead soldiers were named as Mohamed Legouad, 23, and Abel Chennouf, 25; the third victim, Loïc Liber, 27, is from Guadeloupe, a set of French islands in the Caribbean.

The shootings come with a little more than a month to go in a French presidential campaign that has sunk to ugly lows in recent weeks as immigration and the slaughter of animals by kosher and halal religious ritual have been treated as major campaign topics, despite (or instead to detract attention from) more pressing concerns like the European debt crisis. After far-right National Front candidate Marine Le Pen used questionable figures to suggest a secret predominance of halal meat on French dinner tables, President Nicolas Sarkozy, running for reelection, first dismissed, then fomented, then downplayed the concerns, upsetting Jewish and Muslim leaders alike before he met with members of both communities personally to allay their fears. In an apparent play for the far-right votes that cemented his election in 2007, Sarkozy also earned the ire of critics beyond French borders when he declared, “There are too many foreigners on our territory,” while his interior minister and former chief of staff, Claude Guéant, has repeatedly made rhetorical connections between immigrants, delinquents, and fundamentalists.

On Monday political leaders of all stripes were unanimous in condemning the Jewish school attack. The political exercise is delicate so deep into the presidential campaign, with candidates walking a thin line between clearly registering solemn dismay and appearing to play cynically for votes on the back of tragedy.

President Sarkozy traveled to Toulouse immediately to visit the school Monday morning. Outside, in a short speech broadcast live on French news networks reporting nonstop from the scene today, he called the event a “national tragedy” and promised that everything would be done to find the killer. He said a minute of silence would be held in all French schools on Tuesday for the Ozar Hatorah victims.

In a move mooted by pundits, Socialist candidate François Hollande also traveled to the school, echoing President Sarkozy with a short solemn statement on-site, after the Socialist Party declared his campaign suspended for the day. Centrist leader François Bayrou, running fourth in preelection polling, is expected to attend a memorial service in Toulouse later today. Marine Le Pen, meanwhile, openly questioned the appropriateness of a presidential candidate visiting the scene of the crime. “It is the place of the president, but we presidential candidates it seems to me should, above all, be in total solidarity,” Le Pen told reporters. “Because it is precisely in moments like this that there is no more politics, there is no more campaign, there is no more right-wing, there is no more left-wing,” she said. “There are parents—we all are—who are horrified.” She asked that a television channel cancel the political debate show on which she is due to appear Monday evening.

As the tragedy sinks in, the tone of public debate on Monday has largely been dignified. But the head of one of France’s most respected anti-racism groups, SOS Racisme, called on the chattering classes generally to raise the level of debate. Noting the origins of all of those killed, Dominique Sopo, who is also a teacher, said in a statement, “The authorities cannot ignore this reality: it might be that in 2012 in our country, a person is committing racist crimes in cold blood.” Sopo pointed a finger at the “collapse in our country of the word of political, intellectual, and media” about racist discourse. “By dint of agitating scapegoat logic, of hiding our heads in the sand about lacking equality, of combatting with only the greatest discretion the parties on the far-right, what society are we creating if not a society made of blood?”

Monday evening in Paris, Sarkozy spoke again from the Elysée Palace, confirming that the same weapon was used in all three shooting incidents and lifting the terror alert level in the southwest region to scarlet, France’s highest. “We do not know the motivations of this criminal. Of course, in attacking Jewish children and a teacher, the anti-Semitic motivation seems evident,” Sarkozy said. “As far as our soldiers are concerned, we know that two were Muslim, a third West Indian, but we do not know the motivations, even though we can think, we can imagine, that racism and the murderous madness are in the event connected.”

Sarkozy announced that he was “naturally” suspending his re-election campaign until at least Wednesday, the day of the paratroopers’ funeral, which he will attend. Socialist candidate Hollande, meanwhile, has postponed a major campaign rally initially scheduled for Tuesday night in Rennes. Both Sarkozy and Hollande, alongside other French political leaders, attended a memorial service for the victims of the Toulouse shooting Monday evening at a synagogue in Paris.