France's interior minister Bernard Cazeneuve has stated that nearly 900 French citizens have travelled to the Middle East to fight on the side of Islamist groups in Syria and Iraq and some have joined the Islamic State militias.

"There are today nearly 900 from France who are part of this phenomenon, either in the theatre of operations in Syria or in Iraq. There are presumably some in Iraq because the Islamic State in Iraq and the Levant, which recruited them, takes them to all the places where it is engaged in combat," Cazeneuve told France Info radio.

Cazeneuve also announced that France has received hundreds of asylum applications from Iraqi Christians fleeing violence at the hands of the jihadists in the war-torn country.

The development came after the Vatican appealed to Muslim leaders to "unambiguously denounce and condemn" the barbaric practices of the Islamic State against Christians and Yazidis in Iraq. Pope Francis has been vocal in criticising attacks against Christians after 100,000 of them were reported to have fled their homes in Iraq because of the Sunni militants' threat.

France also announced it will supply arms to Iraq's Kurds "in the coming hours" to aid the fight against the Islamic State. Paris received approval from authorities in Baghdad to allow the transfer of arms to the Kurds, according to French media reports.

The increased US assistance in northern Iraq may include a full-scale evacuation of nearly 20,000Yazidi Kurds trapped in the Sinjar mountains, forced to flee by an IS siege on the town of Sinjar.

Security officials are concerned that European militants will ultimately wage jihad against their homelands. In May, French national Mehdi Nemmouche who is suspected to have returned to his homeland from fighting for Islamist rebels in the Syrian Civil War allegedly opened fire at the Jewish Museum of Belgium killing four people.

Nemmouche has also recorded a video flying the flag of the Islamic State.