The attack by two knife-wielding assailants on a church outside Rouen, Normandy, Tuesday in which the attackers killed an elderly priest by slitting his throat and gravely wounded a hostage appears to have been quite deliberately targeted at the Catholic church.

Although attendance numbers are down, Catholicism is still deeply entwined in the national fabric of France, and the attack has already led to outrage across the country.

The goal in going after such a provocative target? To trigger a backlash against Muslims in France and drive the country's Muslims into the recruiting arms of the Islamic State.

The attackers filmed the atrocity, a nun who managed to escape told CNN affiliate BFM.

According to French President Francois Hollande, the attackers claimed they were acting on behalf of ISIS, something the group also claimed via an affiliated news agency.

A French intelligence source told CNN's Christiane Amanpour that one of the attackers had been radicalised after the Charlie Hebdo killings and had tried to enter Syria on two occasions and was associated with Maxime Hauchard, another French jihadi who appeared in an ISIS beheading video in 2014.

In recent weeks European intelligence services have detected a significantly expanded effort by ISIS operatives in Syria and Iraq to directly reach out to extremists in Europe to encourage them to launch attacks. European counter-terrorism officials believe the group is trying to project an image of strength and unleash vengeance, as it loses ground in Syria, Iraq and Libya. This month has already seen ISIS supporters in Europe launch two attacks in Bavaria and a deadly truck rampage in Nice.

In urging attacks on churches, ISIS is trying to eliminate what it calls the “grey zone” for Muslims in the West by provoking a far-right backlash. A drumbeat of attacks in France has led to a groundswell of anti-Muslim anger, which is being stoked and exploited by far-right politicians.

According to France’s National Human Rights Commission (CNCDH) there were 429 anti-Muslim threats and attacks in 2015 – a rise of 223% from the previous year. Marine Le Pen, the leader of France’s far-right national front, reacted to Tuesday’s atrocity by renewing calls for fundamentalist mosques in France to be shut.

ISIS declared an all-out war on Christianity when its fighters beheaded 21 Coptic Christians near Sirte, Libya, in February 2015. “You have seen us [in Syria] chopping off the heads of those carrying the cross [and now] we will fight you altogether,” a masked fighter with a North American accent stated in gruesome video featuring waves of blood flowing northwards into the Mediterranean. The message could not have been clearer: the “Crusader” enemy and all Christians were now seen as one and the same, and all needed to be exterminated. CNN)

•Photo shows Father Jacques Hamel, who was killed during Mass in France by ISIS terrorists.

Update news