France's political leaders have expressed fears of a religious war, after the murder of a Catholic priest marked a grim new direction for jihadi terrorism in the country.

Prime Minister Manuel Valls said the intention of the highly symbolic murder was to “provoke a war of religion in France”.

On Wednesday morning, President Francois Hollande met religious leaders in a bid to calm tensions and prevent further violence.

Who is Adel Kermiche?

The murder of Father Jacques Hamel, 85, has shocked France, where the majority of people identify as Catholic. The priest and four worshippers at the Saint-Etienne-du-Rouvray, near Rouen, Normandy, were held hostage by Adel Kermiche, 19, and another man, who has not yet been identified. They were later shot dead by police.

While France has suffered numerous terrorist attacks in the last 18 months, some observers said the latest atrocity is the first attempt to deliberately target the core, rural section of French society. The priest was killed in a church close to Rouen, where Joan of Arc was martyred in 1431.

In comments reported by the Irish Times, Mr Valls said: “By attacking a priest, in a Catholic church, the objective was to pit French people against each other, to attack one religion to provoke a war of religions.”

In some quarters, there were elements which appeared encourage this. Marion Le Pen, Catholic niece of the right wing Front National party leader, Marine Le Pen, tweeted on Tuesday: “In the West as in the East, Christians must stand up to resist Islam!”

She added: “Faced with the threat that weighs on the France, I decided to join the military reserve. I invite all the young patriots to do the same.”

Normandy church attack in pictures Show all 16 1 /16 Normandy church attack in pictures Normandy church attack in pictures The victim was the 84-year-old priest at the church, Jacques Hamel. AFP/Getty Normandy church attack in pictures French police at the scene of the attack on a church in Saint-Etienne-du-Rouvray, northern France, on July 26 AFP/Getty Images Normandy church attack in pictures More police at the scene BFM TV Normandy church attack in pictures French President Francois Hollande shaking hands with security personnel at the scene AP Normandy church attack in pictures French soldiers standing guard outside the scene of the attack AP Normandy church attack in pictures A policeman secures a position in front of the city hall after two assailants had taken five people hostage in the church at Saint-Etienne-du -Rouvray near Rouen in Normandy Pascal Rossignol/Reuters Normandy church attack in pictures A policeman holds a HKG36 assault rifle as he secures the position in front of the local town hall following the attack REUTERS Normandy church attack in pictures French judicial inverstigating police apprehends a man during a raid after a hostage-taking in the church in Saint-Etienne-du-Rouvray near Rouen in Normandy, France REUTERS Normandy church attack in pictures A French policeman arrests a man following a search in a house on July 26, 2016 in the Normandy city of Saint-Etienne-du-Rouvray, where a priest was killed earlier today in the latest of a string of attacks against Western targets claimed by or blamed on the Islamic State jihadist group. French President Francois Hollande said that two men who attacked a church and slit the throat of a priest had "claimed to be from Daesh", using the Arabic name for the Islamic State group. Police said they killed two hostage-takers in the attack in the Normandy town of Saint-Etienne-du-Rouvray, 125 kilometres (77 miles) north of Paris. / AFP PHOTO / CHARLY TRIBALLEAUCHARLY TRIBALLEAU/AFP/Getty Images AFP/Getty Images Normandy church attack in pictures An undated photo shows French priest, Father Jacques Hamel of the parish of Saint-Etienne. Hamel was killed, and another person was seriously wounded after two assailants took five people hostage in the church at Saint-Etienne-du-Rouvray near Rouen in Normandy, France, July 26, 2016 in an attack on a church that was carried out by assailants linked to Islamic State. Photo Courtesy of Parish of Saint-Etienne via Reuters NO SALES. NO ARCHIVES. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED BY REUTERS AS A SERVICE TO CLIENTS. REUTERS Normandy church attack in pictures The bell tower of the church is seen after a hostage-taking in Saint-Etienne-du-Rouvray near Rouen in Normandy, France, July 26, 2016. A priest was killed with a knife and another hostage seriously wounded in an attack on a church that was carried out by assailants linked to Islamic State. REUTERS/Pascal Rossignol REUTERS Normandy church attack in pictures French policemen stand outside a house during a search in a house on July 26, 2016 in the Normandy village of Saint-Etienne du Rouvray after a priest was killed in the latest of a string of attacks against Western targets claimed by or blamed on the Islamic State jihadist group. French President said that two men who attacked a church and slit the throat of a priest had "claimed to be from Daesh", using the Arabic name for the Islamic State group. Police said they killed two hostage-takers in the attack in the Normandy town of Saint-Etienne-du-Rouvray, 125 kilometres (77 miles) north of Paris. / AFP PHOTO / MATTHIEU ALEXANDREMATTHIEU ALEXANDRE/AFP/Getty Images AFP/Getty Images Normandy church attack in pictures Police officers stand in front of a building during a search operation in Saint-Etienne-du-Rouvray, Normandy, France, following an attack on a church that left a priest dead, Tuesday, July 26, 2016. Two attackers invaded a church Tuesday during morning Mass near the Normandy city of Rouen, killing an 84-year-old priest by slitting his throat and taking hostages before being shot and killed by police, French officials said. (AP Photo/Francois Mori) AP Normandy church attack in pictures Police officers conduct a search in Saint-Etienne-du-Rouvray, Normandy, France, following an attack on a church that left a priest dead, Tuesday, July 26, 2016. Two attackers invaded a church Tuesday during morning Mass near the Normandy city of Rouen, killing an 84-year-old priest by slitting his throat and taking hostages before being shot and killed by police, French officials said. (AP Photo/Francois Mori) AP Normandy church attack in pictures French Interior Minister Bernard Cazeneuve visits the church REUTERS Normandy church attack in pictures A French policeman stands near an armoured vehicle of the French Research and Intervention Brigade (BRI) police during a search in a house on July 26, 2016 in the Normandy village of Saint-Etienne du Rouvray after a priest was killed in the latest of a string of attacks against Western targets claimed by or blamed on the Islamic State jihadist group. French President said that two men who attacked a church and slit the throat of a priest had "claimed to be from Daesh", using the Arabic name for the Islamic State group. Police said they killed two hostage-takers in the attack in the Normandy town of Saint-Etienne-du-Rouvray, 125 kilometres (77 miles) north of Paris. / AFP PHOTO / MATTHIEU ALEXANDREMATTHIEU ALEXANDRE/AFP/Getty Images AFP/Getty Images

A blog post written by Front National in reaction to the attack said: “It is now the heart of the cultural identity of our nation that is intentionally touched.” This sentiment is likely to be shared among French society more broadly.

But others have called for restraint. In a statement, the Archbishop of Rouen, Dominique Lebrun, said: “The Catholic Church can take up no other weapons than prayer and fraternity between men.”

Mohammed Karabila, president of the Regional Council of the Muslim Faith for Haute-Normandie, frequently met with Father Hamel as part of an interfaith council and considered him a friend.

“I don’t understand, all of our prayers go out to his family and the Catholic community,” Mr Karabila said. “He was someone who gave his life to others. We are stunned here at the mosque.”

Of his conversations with Father Hamel, Mr Karabila said: "We talked about religion and how to live together.

"It has been 18 months that civilians have been attacked, now they are attacking religious symbols, using our religion as a pretext. It is no longer possible."

Previous jihadi attacks in France targeting other religions have focused on murdering Jewish people. In January 2015, a kosher supermarket was attacked by gunman Amedy Coulibaly. The consequent siege resulted in the death of four hostages and hurt nine more.