PARIS — A jihadist involved in the brutal killing of an elderly priest pledged to attack France in a newly released video, as Catholic bishops called for a day of prayer in a nation shaken by the latest assault.

The assailant has been named as 19-year-old Abdel Malik Petitjean, who was listed in June on France’s "Fiche S" system of people posing a potential threat to national security after he tried to reach Syria from Turkey.

Petitjean threatened France and directly addressed President Francois Hollande and Prime Minister Manuel Valls in the footage released by the Islamic State-linked Amaq news agency.

Dressed in a striped t-shirt, Petitjean speaks mostly in French but uses some Arabic phrases, and appears to be filming in a home.

Petitjean, whose face was disfigured when he was shot dead by police, had been harder to identify than his accomplice Adel Kermiche, also 19.

Investigators confirmed his identity after a DNA match with his mother.

The pair pledged allegiance to the Islamic State group in a video made before they stormed a church in the Normandy town of Saint-Etienne-du-Rouvray on Tuesday and slit the throat of 86-year-old priest Jacques Hamel at the altar.

The president of the Conference of Bishops in France Georges Pontier called on all Catholics in the country to observe a day of national prayers and fasting Friday "for our country and for peace in the world".

"We have various sentiments at this time. We know well that the only brotherhood, in our country, is the voice that leads to lasting peace. Let’s build it together," he said in a statement earlier this week.

Hamel’s funeral will be held in the Gothic cathedral of nearby Rouen next Tuesday.

’Government guilty’ 

The church attack came as the government was already facing a firestorm of criticism over alleged security failings after the Bastille Day truck massacre in Nice that left 84 people dead two weeks ago.

A brief show of political unity at a mass attended by different faiths in Paris on Wednesday quickly dissolved as Prime Minister Manuel Valls and Interior Minister Bernard Cazeneuve faced fresh calls to resign.

"Even if the government is not responsible for the wave of terrorism, it is guilty of not having done everything to stop it," Laurent Wauqiez, the deputy leader of the right-wing Republicans party, said in an interview.

Meanwhile, President Francois Hollande responded to remarks by US Republican presidential candidate Donald Trump that "France is no longer France" as a result of the attacks.

"France will always be France, because France will never yield and because France is always the bearer of ideals, values and principles, for which we are recognised throughout the world," he said.

The French government has said that everything possible is being done to protect citizens, while warning that more terror attacks are inevitable, after three major strikes and several smaller attacks in the past 18 months.

Hollande on Thursday confirmed plans to create a National Guard drawn from existing reserves, after the government previously urged "patriots" to sign up to become reservists.

The president said he hopes the guard, made up of volunteers from the police, paramilitary police and military, will be operational by early autumn.

Tough questions

The government has faced tough questions since it emerged that both church attackers had been on the radar of intelligence services and had tried to go to Syria.

Sparking particular ire was the revelation that Kermiche had been released from prison while awaiting trial on terror charges after his second attempt to travel to Syria.

He was fitted with an electronic tag -- allowing him out of the house on weekday mornings -- despite calls from the prosecutor for him not to be released.

Petitjean, from France’s eastern Savoie region, had several part-time sales jobs and was described by his incredulous mother as "gentle", insisting he "was not involved at all".

Others who knew him were equally shocked, describing him as normal and showing no signs of radicalisation.

The attack is the third in two weeks in France and Germany in which jihadists have pledged allegiance to IS, increasing jitters in Europe over young, often unstable men being lured by the group’s propaganda and calls to carry out attacks on home turf. — AFP