Islamic State says the church attack in France was carried out by two "soldiers" from the group.

French president Francois Hollande had earlier suggested that the Islamic State group is behind the church attack in Normandy that left an 84-year-old priest dead.

Two attackers killed the priest by slitting his throat before being shot and killed by police after they seized hostages in a church in Normandy.

Archbishop Dominique Lebrun of Rouen confirmed the identity of the priest as Father Jacques Hamel, 84.

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Pope Francis has condemned the attack on the church in the strongest terms.

Another person inside the church near the city of Rouen was seriously injured and is hovering between life and death, Interior Ministry spokesman Pierre-Henry Brandet said.

Police rescued three people from the church in the small north-western town of Saint-Etienne-du-Rouvray, said Mr Brandet. The hostage-taking occurred during morning Mass, he told reporters.

Police said two attackers entered Father Hamel's church in the small Normandy town of Saint-Etienne-du-Rouvray, slit his throat and took hostages before being shot dead by police.

Vatican spokesman, the Rev Federico Lombardi, said the attack hits particularly hard "because this horrific violence took place in a church, a sacred place in which the love of God is announced, and the barbaric murder of a priest and the involvement of the faithful."

Glasgow Times:

Rev Lombardi called the attack "more terrible news, that adds to a series of violence in these days that have left us upset, creating immense pain and worry."

He said the pope has expressed "pain and horror for this absurd violence, with the strongest condemnation for every form of hatred and prayer for those affected."

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The Vatican expressed its closeness to the Roman Catholic Church in France and the Archdiocese of Rouen, as well as to the affected communities and the people of France.

In a statement from Krakow, Poland, where Pope Francis was visiting, Archbishop Lebrun said: "I cry out to God, with all men of good will. And I invite all non-believers to unite with this cry ... The Catholic Church has no other arms besides prayer and fraternity between men."

The identities of the attackers and motive for the attack are unclear, according to a security official.

The slaying "is obviously a drama for the Catholic community, for the Christian community," Mr Brandet told reporters.

Francois Hollande and interior minister Bernard Cazeneuve were heading to the town.

Mr Brandet, speaking on BFM TV, said the RAID special intervention force was searching the church and its perimeter for possible explosives and terrorism investigators had been summoned.

France is on high alert after an attack in Nice on Bastille Day - July 14 - that killed 84 people and a string of deadly attacks last year claimed by the Islamic State group that killed 147 others.

The country is also under a state of emergency and has extra police presence in the wake of the Nice attack in which a man barrelled his truck down the city's famed Promenade des Anglais, mowing down holiday crowds.

Islamic State extremists have urged followers to attack French churches and the group is believed to have planned at least one church attack earlier.

In April 2015, an Algerian student who was arrested after shooting himself in the leg was found with heavy weapons, bulletproof vests and documents linked to Islamic State.

He is charged with killing a young woman inside her car the same day. According to French authorities, the suspect, Sid Ahmed Ghlam, was sent by the Belgian Abdelhamid Abaaoud to attack a church in Villejuif, just outside of Paris.

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A cell directed by Abaaoud later carried out the November 13 attacks in Paris that left 130 people dead and the March 22 attacks in Brussels that killed 32 people.