ISIS fighter in Raqqa, Syria
ISIS fighter in Raqqa, SyriaReuters

Video has emerged showing a chilling rally in Holland, during which dozens of young Muslims flew the black flag of the "Islamic State" group (formerly ISIS) and chanted "Death to the Jews!" in Arabic (maut al Yahud!)

The demonstration appears to be the same incident following which two Arab men were arrested on July 31, on suspicion of "inciting violence against people of a specific belief or race".

Astonishingly, Arabic-speaking police who monitored the event (but did nothing to intervene) initially reported that "the slogans overheard by this officer were not considered as crossing boundaries. Hence no arrest was made."

The rally took place in Holland and appears to be the first such open mass display of support in western Europe for ISIS - which rebranded itself as "the Islamic State" or "Caliphate" following massive territorial conquests in Iraq.

One Dutch MP asked why a pro-ISIS rally was allowed to held in the first place.

"What are these kids doing there in the first place? ISIS is pure barbarism, it is bloodthirsty," Labor MP Ahmed Marcouch asked in an interview with The Daily Beast, noting that ISIS was a danger to the Muslim community as well. "We can’t allow them to win our children away from us."

Anti-Semitism in Europe has risen dramatically in recent weeks, primarily fueled by Muslim extremists who have used Israel's military operation in Gaza as a springboard for unprecedented incitement and violence.

Yesterday, Italian authorities announced the deportation of a Moroccan-born imam who called to "kill the Jews" at an inflammatory sermon in an Italian mosque.

France, Germany, Spain, Belgium and the UK are just some of the other European countries where high-profile anti-Semitic attacks have occurred at the hands of ostensibly "pro-Palestinian" supporters, drawing condemnation from the UN Secretary General.

In eastern Europe, some far-right groups such as Hungary's Jobbik party (which itself has flirted with Islamist groups as part of a "common front" against Israel) have themselves sought to use pro-Gaza sentiment to stoke anti-Zionist and anti-Semitic hatred.