TOULOUSE, France (Reuters) - French police stepped up the search on Tuesday for a gunman who apparently filmed the scene as he shot dead three children and a rabbi at point-blank range in a Jewish school, warning that he had already killed twice last week and could strike again soon.
Authorities believe the scooter-riding gunman is a methodical, trained marksman with "extremist" views who was also responsible for last week's fatal shootings of three soldiers of North African origin.
France's President Nicolas Sarkozy has said racism appeared to be the motivation for Monday's school attack, which came just five weeks before the first round of the presidential election.
Immigrants and Islam have been major themes of the campaign as Sarkozy tries to win over the voters of far-right leader Marine Le Pen. Analysts say the shootings could transform the election debate and possibly tone down populist rhetoric.
"This is someone who has killed every four days, who is extremely organised, who has a high-calibre weapon," Paris Prosecutor Francois Molins told a news conference.
"We're up against an extremely determined individual, who knows he's being hunted and could strike again."
Molins said the shooter wounded Rabbi Jonathan Sandler as he entered the Ozar Hatorah school, where he cornered eight-year-old Myriam Monsonego and shot her in the head. He then returned outside and shot Sandler and his two children, who had rushed to his side, at point blank range.
France is home to the largest Jewish and Muslim communities in Europe and has a history of attacks on both groups, but Monday's shooting was the most deadly anti-Semitic attack on French soil in nearly 30 years.
The police tightened security at religious sites, raising the terror alert in the southern town to the highest level of 'scarlet' for the first time ever in France, and talked to gun clubs in an effort to track down the killer.
"We will track down this monster," said Foreign Minister Alain Juppe, who was due to fly to Israel with the bodies of the four Jewish victims for their burial on Wednesday. "We will find him, bring him to justice and punish him."
The gunman is also the prime suspect in the killing of three paratroopers in two separate shootings last week in Toulouse and the nearby town of Montauban. A fourth soldier of Caribbean origin was in coma after Thursday's shooting in Montauban.
In each attack, the gunman arrived on a Yamaha scooter and used the same Colt 45 handgun. His face was hidden by a motorcycle helmet during the attacks.
Interior Minister Claude Gueant said the gunman wore a "GoPro" camera around the neck on Monday - a type often used by extreme sports enthusiasts to record their exploits.
"This shows a profile of the murderer as someone who is very cold, very determined, with precise gestures, and therefore very cruel," Gueant said.
Anti-Islamist Anders Behring Breivik, who massacred 69 people in Norway last summer, recommended in a manifesto he posted on the Internet that aspiring mass murderers use the camera "to document your operation".
Police excluded any link to three former soldiers expelled from the 17th parachute regiment in Montauban in 2008 for neo-Nazi activities.
An overnight vigil was held at the Ozar Hatorah Jewish school in Toulouse, a five-storey brick building in a leafy residential neighbourhood, where residents and parents left floral tributes and candles in memory of the victims.
Mourners said Sandler's widow, Eva, delivered a heart-rending speech, accompanied by her surviving daughter.
"It was very difficult and painful to see the little coffins. We are in shock," said Arie Bensemhoun, spokesman for the Jewish community in Toulouse. "But we know we are sharing this grief with all our citizens and perhaps something good will come from this for the country. The time has come for healing."
Hearses carrying the bodies of the four victims, who hold dual French-Israeli nationality, were surrounded by sobbing children in prayer caps as they left the school to be transported to Paris. From there, they will be flown to Israel for burial on Wednesday morning, accompanied by Juppe, who was due to voice France's determination to catch their killer.
One girl who survived the attack spoke of her sheer terror as the shots rang out through the school.
"The headmaster was shouting there had been a shooting and they put us all together in a big room," the girl, accompanied by her mother, told Reuters. "I didn't see anything but I heard the shots. It was terrifying. I thought he was coming for us."
Schools all over France observed a minute of silence.
"This has happened in Toulouse, in a religious school with children from Jewish families, but it could have happened here. The same killer could have come here, these children are exactly like you," Sarkozy said, attending the silent vigil in a Paris secondary school.
France's Jewish umbrella group Crif, which is organising a remembrance march for the victims in Paris on Sunday, welcomed the decision to suspend election campaigning until Wednesday when political leaders of all colours were due to attend a burial ceremony for the soldiers in Montauban.
Analysts said the killings would change the election debate.
"The tone of the campaign cannot go back to what it was," said Dominique Reynie, head of Fondapol politics institute.
"The campaign was dominated by an aggressive tone and a strong degree of populist rhetoric. This rhetoric will cease because there will be voter demand for healing."
France's far-right leader Marine Le Pen is running third in the race for the presidency and this has helped to draw issues of race and immigration into the election campaign.
The centre-right Sarkozy has tried to attract her voters with a pledge to halve immigration and criticism of halal slaughter as he lags Socialist Francois Hollande in voting intentions polls.
Some analysts said there would be a discussion about whether Sarkozy has stirred feelings that led to the attack.
"There will be more debate, notably on whether the tension created in society by Nicolas Sarkozy and the UMP (ruling party) has not somehow provoked or facilitated this type of violence," said L'Express magazine editor-in-chief Christophe Barbier.
Juppe said the campaign could not have triggered the shooting.
"Anti-Semitism exists in France, we have fought it for years," he said.
"Nobody should try to benefit in any way from this drama, which is in no way linked to the electoral campaign."
Additional reporting by Geert De Clercq, Emmanuel Jarry and Marine Pennetier in Paris and Balazs Koranyi in Oslo; writing by Geert De Clercq and Daniel Flynn; Editing by Anna Willard and Giles Elgood