"Keep the world clean," read one of the placards with the drawing of a wastebasket and an Israeli flag inside carried by the protesters taking part in a pro-Palestinian demonstration in Warsaw on Saturday.
They also carried Palestinian flags or banners calling for an end to "genocide of Palestinians" and for a free Palestine.
"Such a thing should never happen," Pawel Jablonski wrote on the X platform later on Saturday, referring to the banner with the Israeli flag inside a wastebasket. He also placed the photo of the banner on X.
"Banners calling for ethnic and national hatred violate the law and are the reason for dissolving a gathering," Jablonski wrote.
"Responsibility for the lack of response is falling on (Warsaw mayor) Rafal Trzaskowski and the city authorities," he said.
Jablonski stated that in the case of an Independence March or any other patriotic gathering Warsaw's authorities "had no qualms."
"They imposed a ban and dissolved them under any pretext," he said. "And complete silence now," the deputy minister wrote.
The same photo and another one showing police presence at the march was placed on social media on Saturday night by Israeli Ambassador to Poland Yacov Livne, who wrote that Poland's authorities are obliged to prevent signs of such open anti-Semitism.
The Israeli embassy in a tweet posted on X late on Saturday, called on Polish police and the Medical University of Warsaw, where the person carrying the placard is said to be a student, to take action.
"Polish police @PolskaPolicja & Medical University of Warsaw need to act," the embassy wrote. "No place for Antisemites!"
The Saturday march in Warsaw was one of many pro-Palestinian demonstrations organised in many European and world countries.
Authorities in Gaza say that more than 4,380 people have been killed and over 13,600 have been injured in the territory since the war began.
Over 1,400 people were killed in Israel during Hamas's deadly attack on October 7. At least 203 civilians have been kidnapped. (PAP)
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