Pro-Palestinian students last week directed threats of violence and anti-Semitic slurs at pro-Israel students at the University of Michigan.

University police said they learned of the incident after two “Arab males” shouted “threats of violence” at a student who refused to support the Boycott, Divestment and Sanctions (BDS) movement against Israel during a sit-in by pro-Palestinian students at the university’s student union, the Washington Free Beacon reported. Other pro-Israel students had allegedly been called anti-Semitic slurs such as “kikes” and “dirty Jews.”

The sit-in was organized by the pro-Palestinian group “Students Allied for Freedom and Equality” in response to the recent decision by the school’s student government to indefinitely table an Israel divestment resolution, the Michigan Daily reported. In response, university officials brokered an apology by the student government president and ensured that the vote on the divestment bill will be conducted soon.

Jacob Baime, executive director of the Israel on Campus Coalition, called on University of Michigan officials to protect its students from “violent threats.”

“The hateful anti-Israel BDS movement is reaching new depths of depravity,” Baime told JNS.org. “This isn’t about Israel as much as it is about free speech. Students have the right to express their views without fear of physical harm.”

Kenneth Marcus, president of the Louis D. Brandeis Center for Human Rights Under Law and a former staff director of the U.S. Commission on Civil Rights, told JNS.org that while he sees “lots of cases where it is hard to say whether anti-Israel activists are actually bigots or whether they are just misguided,” in the Michigan case—where anti-Semitic slurs were used—that is “not even a close question.”

“The University of Michigan needs to act quickly to make clear that this kind of abuse will not be tolerated,” Marcus said.

“There is a difference between criticizing Israel and being anti-Semitic, although the former often crosses the line into the latter,” he said.