PARIS _ A pair of attackers armed with knives slipped into a Roman Catholic church in northern France on Tuesday during morning Mass and killed an elderly priest by slitting his throat before being shot dead by police, French officials said.
Islamic State claimed responsibility for the attack through its affiliated Amaq news agency. It was the latest of a string of bloody episodes in France and Germany over the past two weeks, which have dramatically heightened fears over jihadist-inspired acts of terror and galvanized debate over Europe's ability to absorb a wave of immigrants, many of them from strife-torn countries such as Syria.
The slain priest, Jacques Hamel, was in his mid-80s, and French news reports described him as a beloved figure who had spent decades ministering to parishioners in Normandy. An auxiliary priest who had retired a decade ago, he sometimes filled in for the regular parish priest in celebrating Mass, as he did Tuesday morning.
Only two nuns and two worshippers witnessed the horrific scene. One of the nuns, named in an interview as Sister Danielle, recounted the execution to French television.
"Everyone was shouting, 'Stop!' We cried 'Stop, stop, you don't know what you're doing,' but they forced him to his knees," she told BFM-TV. The attackers shot video of themselves making an Arabic-language statement from the altar before killing the priest, she said.
In the chaos while the assailants were "occupied with their knives," Sister Danielle managed to slip away and raise the alarm, she said.
"It was a horror," she said. "Jacques was an extraordinary priest. ... He was a great man, was Father Jacques."
Hubert Wulfranc, the mayor of Saint-Etienne-du-Rouvray, was in tears as he addressed journalists Tuesday after French President Francois Hollande's visit. "France is grieving," he said. "Let's unite in tears and stand against the barbarity."
French officials quickly called in terrorism investigators, and even before the claim of responsibility was reported in the church attack, Hollande cast blame on Islamic State.
Hollande _ under heavy public criticism over perceived security lapses in connection with a July 14 truck rampage in the French Riviera city of Nice that killed 84 people _ swiftly headed for the scene of Tuesday's assault, in the Normandy town of Saint-Etienne-du-Rouvray. A suburb of the city of Rouen, the town is about 65 miles northwest of Paris.
"We are facing a group ... that has declared war against us," the French president told reporters, referring to Islamic State by its Arabic-language acronym, Daesh. "It was not Catholics who were targeted; it was all the people of France."
The claim of responsibility issued via the Amaq agency _ which, in keeping with usual practice, quoted a "security source" in Islamic State _ said the perpetrators of the church attack were two of the group's "soldiers," adding: "They executed the operation in response to calls to target the nations of the Crusader alliance."
The group often uses the term "crusaders" to refer to nations that have joined in the U.S.-led bombing campaign against Islamic State. France is among them.
A leader of a local Muslim center in Normandy, Mohammed Karabila, said one of the assailants, who were not immediately identified by authorities, had been known to police. The Associated Press quoted Karabila as saying the attacker was placed under watch by security services after he traveled to Turkey. Turkey is a major gateway for fighters headed to Syria.
Denunciations of the attack poured in. The Vatican, in a statement, condemned the "barbaric killing." French clerics called for a memorial tolling of church bells across the country to mourn Hamel.
"I cry out to God ... and I invite all nonbelievers to unite in this cry," Archbishop Dominique Lebrun said in a statement.
An Interior Ministry spokesman, Pierre-Henri Brandet, told journalists that a bomb squad and bomb-sniffing dogs had been dispatched to the scene, but there was no immediate indication that any explosives had been found.
The church assault came as France was still reeling from the Bastille Day strike in the southern city of Nice, in which a Tunisian-born deliveryman barreled along a seaside promenade, mowing down spectators who had just watched a fireworks display.
Authorities described the attacker as having been recently radicalized. Family members in Tunisia said he had a long history of violence and mental instability.
Of the Normandy attack, Islamic State's news agency said: "The perpetrators of the Normandy Church attack in France are two soldiers of Islamic State; they executed the operation in response to the calls to target the nations of the Crusader alliance."
The attack sent fresh shock waves across France, which is predominantly Roman Catholic. The church remains a revered institution, even though many French Catholics adhere only nominally to the church's stricter tenets.
Neighboring Germany, too, has suffered a recent wave of attacks. On July 18, a knife and ax-wielding Afghan teen injured five people before being killed by police.
Four days later, the country's third-largest city, Munich, was locked down for hours after an Iranian German teenager gunned down nine people before killing himself; though investigators found no link to terrorism in that attack, it shook a nation that does not often experience mass shootings. Over the weekend, a Syrian refugee killed a woman with a machete _ an incident of violence also not linked to terrorism. The same day, another Syrian man blew himself up outside an open-air music event in southern Germany, injuring several attendees; Islamic State claimed that attack.
