Mourners carry the body of Palestinian Islamic Jihad militant Sweilem, whom medics said was killed in an Israeli air strike, during his funeral at Jabalya refugee camp in northern Gaza Strip
Mourners carry the body of Palestinian Islamic Jihad militant Mohammed Sweilem, whom medics said was killed at an Israeli air strike, during his funeral in Jabalya refugee camp in the northern Gaza Strip July 12, 2014. Israel pounded Palestinian militants in the Gaza Strip on Saturday for a fifth day, killing nine people including two disabled women according to medics, and showed no sign of pausing despite international pressure to negotiate a ceasefire. Reuters

The head of Germany's domestic intelligence agency has said the anticipated attack by the ISIS on Europe will "just be a matter of time" as more and more young people get enticed to join the terror group, lured by its "brutality, radicalism and rigour."

Hans-Georg Maassen, head of Germany's BfV domestic intelligence agency, said young people are attracted into joining ISIS because they find the organisation "more authentic" than al-Qa'ida or even its affiliate, the Jabhat al-Nursa.

"Al Qaeda fades besides the Islamic State when it comes to brutality," Maassen said.

In fact, Germany's intelligence authorities surmised there at least 400 German nationals currently believed to be fighting alongside ISIS as the group wreaks havoc and fear in Iraq and Syria.

He said the Internet played a very pivotal role in recruiting the European youngsters. One such German propaganda was in November 2013, when a German Muslim convert in Syria released a video calling for his countrymen to join in jihad.

The German converts "Abu Osama," a name he said he picked because he "loves Osama bin Laden," speaking in German, urged Muslims around the world to come to Syria and fight along with them. He likewise urged for the establishment of a caliphate so they can impose the Islamic law worldwide.

He even said in the video that "we love death and we will win here."

The BfV estimated there are at least 43,000 Islamists currently in Germany. The group particularly sees an increase in membership growth in the ultra-conservative Salafi movement.

Maassen does not discount the fact those currently fighting with ISIS will come back to their native homeland.

"We have to assume... that there may well be people who return and commit attacks," he said.

On Sunday, German Chancellor Angela Merkel called for a vote to send military aid to the Kurdish forces battling the militant group.

She said the alarming success rate of German jihadists recruits is enough reason for Germany to reconsider its policy made after the war by not sending arms to areas of conflict. Even just this once.

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