AMSTERDAM (JTA) — Participants in a rally in Rotterdam that was co-organized last month by a Hamas operative and promoters of a boycott against Israel shouted in Arabic about killing Jews, leaders of Dutch Jewry said.

The incident occurred on July 22 during a rally advertised by a newly-formed organization called the Palestinian Community in the Netherlands, or PGNL, according to a statement Wednesday issued by the Dutch Central Jewish Board. The Rotterdam branch of the Boycott, Divestment and Sanctions movement, which also advertised the event on its Facebook page, was the real organizer of the rally, according to the statement.

On July 21, BDS Rotterdam shared on Facebook a call to attend the rally by Amin Abou Rashed, a senior operative of the Al Aqsa Foundation, which the Dutch secret service and judiciary in 2003 flagged as a Hamas front and banned.

Participants in the rally, which was to protest the use of security measures by Israel around the Al Aqsa mosque following a deadly terrorist attack there, shouted in Arabic: “Jews, remember Khaybar, the army of Muhammad is returning.”