Assailants linked to Islamic State slit the throat of an elderly priest and took several worshippers hostage in a French church on Tuesday before police shot the attackers dead.

It was the latest in a wave of attacks in Europe inspired by the Islamist militant group based in Iraq and Syria that is on the defensive against a U.S.-led military coalition in which France is a major partner.

Police said the knifemen entered the church during morning mass near the northern city of Rouen, west of Paris, killing Father Jacques Hamel, an 85-year-old parish priest, and taking four other people hostage, one of whom was seriously wounded.

Police shot the attackers dead as they emerged from the church with their hostages.

Speaking at the scene of the attack in the Normandy town of Saint-Etienne-du-Rouvray, President Francois Hollande said Islamic State had declared war on France and the state should “use all its means” within the law to fight the militant group, against which France has launched air strikes in Syria and Iraq.

The president called it a “dreadful terrorist attack” and told reporters the attackers had pledge allegiance to IS. The IS news agency Amaq said two of its “soldiers” were involved.

“The threat remains very high,” Hollande said.

The attack was the latest in a string of deadly assaults including the mass killing in Nice, southern France, on Bastille Day 12 days ago and four incidents in Germany, most recently a suicide bombing at a concert in Ansbach on Sunday.

IS has called for its supporters to take action with any available weapons targeting countries that it has been fighting.

The investigation was handed to the anti-terrorist unit of the Paris prosecutor’s office.

Several French media reported that one of the knifemen was a local man who had spent a year in jail on his return from Turkey after being intercepted trying to travel to Syria, but had been freed on bail with an electronic tag pending trial for alleged terrorism offences.

The prosecutor’s office said the identification of the two suspects was still under way and it was too early to jump to conclusions about a possible link.

Police said one person had been arrested in connection with the attack.

SLAIN PRIEST

Without waiting for such details, ex-president Nicolas Sarkozy, expected to enter a conservative primary soon for next year’s presidential election, jumped on the latest incident to accuse the Socialist government of being soft on terrorism.

“We must be merciless,” Sarkozy said in a statement to reporters. “The legal quibbling, precautions and pretexts for insufficient action are not acceptable. I demand that the government implement without delay the proposals we presented months ago. There is no more time to be wasted.”

The center-right opposition wants the government to put all Islamist suspects subject to a confidential security notice under administrative detention to avert potential attacks.

Far-right National Front leader Marine Le Pen, also expected to run for the presidency, said both major parties had failed on security. “All those who have governed us for 30 years bear an immense responsibility. It’s revolting to watch them bickering!” she said on Twitter.

Hollande insisted that the government must stick to the rule of law, which was what the hallmark of a democracy.

Pope Francis condemned what he called a “barbarous killing”.

“The fact that this episode took place in a church, killing a priest, a minister of the Lord and involving the faithful, is something that affects us profoundly,” Vatican spokesman Father Federico Lombardi said.

The attack heaped yet more pressure on Hollande to regain control of national security, with France already under a state of emergency 10 months ahead of a presidential election in which he is widely expected to seek a second term.

The Normandy attack came less than two weeks after a 31-year-old Tunisian, Mohamed Lahouaiej Bouhlel, plowed his heavy goods truck into a crowd of revelers in the French Riviera city of Nice, killing 84 people. Islamic State claimed that attack.

“Everything is being done to trigger a war of religions,” tweeted Jean-Pierre Raffarin, a former conservative prime minister who now heads the Senate’s foreign affairs committee.

Hollande visited the Normandy town with Interior Minister Bernard Cazeneuve, meeting survivors of the church attack and members of the emergency services.

Cazeneuve has come under fire from conservative politicians for not doing enough to prevent the Nice attack, which prompted lawmakers to approve a six-month extension of emergency rule.