French prosecutors have opened an anti-terrorism investigation into a string of shootings in southern France that have left three Jewish schoolchildren, a rabbi, and three paratroopers dead. The latest attack came Monday, when a man riding a motorcycle opened fire at the Jewish school Ozar Hatorah in the city of Toulouse, murdering four people. "The killings are the worst suffered by France's small Jewish community in decades," says Robert Marquand in The Christian Science Monitor, "and the impact here is being compared to the Columbine High School shootings in the United States in 1999 or last summer's massacre of Norwegian youth at a youth political camp." Making matters worse, in two related incidents — on March 10 in Toulouse and on March 15 in the nearby town of Montauban — three paratroopers of North African or Caribbean origin (two of whom were Muslim) were shot dead by a man on a motorcycle. Here's what you should know:

Are the three shootings connected?
It seems they are. Police say the same "powerful" .45-caliber handgun used in Monday's school shooting was also used to kill the three paratroopers. And "all the targets apparently have been ethnic minorities," says CBS News. Indeed, in each case, the killer "used the same gun, rode the same 500cc Yamaha scooter, and acted with the same cold-blooded brutality," says Hugh Schofield at the BBC.

Why is this happening?
Although it's still too early to be sure, "the attacks raise questions about possible religious or ethnic motives — and feed into ongoing concerns about anti-Semitism in France," says Lisa Bryant at Voice of America. France has the largest Jewish community in western Europe, estimated at about 500,000 people, as well as the largest Muslim population in western Europe, about 5 million. In recent years, as the Muslim community has grown, tension has risen "in a society pledged to secularism but deeply rooted in Christianity," says Edward Cody at The Washington Post. Maybe the killer is a "deranged far-rightwinger," says Schofield. "Could he be a neo-Nazi type — maybe an ex-soldier or a member of the criminal underworld — with a hatred of all minorities, Jews and Muslims?"

Any other theories?
Because he appears to have targeted uniformed paratroopers, Schofield suggests, it's possible "that the killer hates soldiers because of France's military presence in Afghanistan. So maybe — some are saying — he could be a deranged Islamist, which would also explain his hatred of Jews." Yes, it's possible, says Michael Goldfarb at Global Post, that the killer is "a jihadi" targeting "people he regarded as turncoat collaborators with oppressors of Muslims, i.e. the soldiers; and representatives of Zionism — as all Jews are considered to be" by such extremists.

What does the government say?
French President Nicolas Sarkozy says the shootings are motivated by racism. And Prime Minister Francois Fillon has asked for all schools and religious buildings to be secured until the suspected killer is found. Meanwhile paratroopers have been asked not to wear their uniforms if they are not on duty, says Thierry Burkhard, a Defense Ministry spokesman. But fear not, says Schofield: "With one of the biggest manhunts in French history under way," it's only a matter of time before the suspect is found.

Sources: Associated Press, BBCCBS News, Fox News, Global PostVoice of America, The Washington Post