Polish police are investigating antisemitic signs that were spotted among banners that pro-Palestinian, anti-Israel students hung outside a Krakow university building that they have occupied for over six months, local media reported Thursday.

The Gazeta Wyborcza newspaper said the signs, including one reading “Jews to the gas,” were spotted Monday morning on a wall outside the Collegium Broscianum, which houses the sociology and philosophy departments of the Jagiellonian University, Poland’s oldest university, which has a long history of antisemitism.

A university spokesman apologized for the incident, saying the institution swiftly removed the signs and alerted the local police, who confirmed investigating the “incitement to hatred on national grounds.”

Academy for Palestine, the student group occupying the building, denied putting up the signs, calling them a “provocation,” the news outlet reported.

Israel’s Ambassador to Poland Yacov Livne took to X Friday to condemn the “Israel-haters” at the university who “apparently want to murder Jews by gas, as was done in nearby Auschwitz.”

“I call on the Polish authorities to look closely into the events taking place on this campus,” he added.

Decrying the “call for genocide” at the university, Krakow’s religious Jewish community said on Facebook that since the Hamas onslaught on October 7, 2023, “acts of antisemitism are on the rise, which until now — like the infamous March 68 campaign — was hidden behind a facade of alleged ‘anti-Zionism.'”

The community was referring to a purge of Polish Jews from academia after Communist Poland’s crackdown on student protests. Poland, then in the orbit of the Soviet Union, said at the time that anti-Zionism, not antisemitism, was behind the purge, which came after Moscow cut ties with Israel following the 1967 Six Day War.

Jagiellonian University, one of Poland’s most prestigious institutions, was founded in 1364, and is known as the birthplace of the Copernican Revolution.

The Israel Hayom newspaper said the university was initially closed to Jews, and university students would occasionally participate in anti-Jewish riots. In the years before the Holocaust, the newspaper said, Jewish students were segregated from other students.

Israel Hayom said Jewish and Israeli students currently studying at the university feel threatened by the “antisemitic bullying” around them, and that the university and local authorities have left their pleas for help unanswered.

Citing a police spokesperson, Dziennik Polski reported that the anti-Israel encampment at the university’s Collegium Broscanium had cleared the premises on Tuesday per an agreement reached with university authorities on September 30.

In return, the university said it will try to avoid cooperating with research that could be used to develop Israel’s military, and will assess further cooperation with Israeli academia.