Pro-Palestinian demonstration (file)
Pro-Palestinian demonstration (file) Reuters

Dutch police have arrested two people for allegedly chanting "Death to the Jews" at a pro-Palestinian demonstration, the public prosecutor's office said on Thursday.

"They are suspected of inciting violence against people of a specific belief or race," the prosecutor's office said in a statement after the men, both 32, were arrested early Thursday.

The Hague mayor Jozias van Aartsen has been hit by a wave of criticism for failing to act against alleged anti-Semitism at two pro-Gaza demonstrations earlier this month amid Israel's operation on the Hamas-run enclave to stop deadly rocket fire and destroy tunnels for infiltration attacks inside Israel.

The arrests came in connection with the second demonstration on July 24, during which some protesters carried black flags associated with Islamist terrorists, including the Islamic State (formerly "ISIS") that has proclaimed a "caliphate" encompassing parts of Syria and Iraq.

An Arabic-speaking policeman reportedly said at the time that "no lines were crossed", while video footage emerged of people chanting "Death to the Jews" in Arabic.

"The prosecutor's office and two interpreters watched images from the demonstration... the two interpreters independently translated words that would be punishable," the prosecutor's statement said.

The Simon Wiesenthal Centre wrote to Van Aartsen earlier this week saying he may have contravened Dutch anti-terrorism legislation by allowing demonstrators to carry the jihadist flags.

The letter expressed "shock at your authorization, on two occasions, of demonstrations in the Hague... calling for 'the death of Jews'."

Also on Thursday, extremists hurled a firebomb at Jewish woman's house after she flew an Israeli flag outside her home.

According to the Het Parool daily the firebomb landed on the balcony of an apartment next to that of Mexican-born Leah Rabinovitch, who has received death threats after hanging the flag in a neighborhood of the city with a large Moroccan Muslim population. One death threat she received read "Heil Hitler, Hitler is coming back, Jews must die." Assailants also threw a rock through the window of her home.

Anti-Semitism in Europe has soared in recent weeks as anti-Israel extremists have increasingly targeted Jews throughout the continent.