(JTA) — A prominent Hebrew University professor was shouted down by two dozen protesters at the beginning of a lecture at the University of Minnesota in Minneapolis.

The protesters delayed the speech by Moshe Halbertal, a member of the New York University Law School faculty, for 30 minutes on Tuesday afternoon, the Washington Post reported.
Halbertal, who co-authored the Israel Defense Forces’ most recent code of ethics, had been scheduled to deliver the University of Minnesota’s annual Dewey Lecture in the Philosophy of Law, and approximately 100 students and faculty had gathered to listen.

The protesters stood up “one by one” to “shout denunciations of Israel” before university police escorted them out of the lecture hall, according to the Post.

Outside the hall the protesters — members of the Anti-War Committee, Students for a Democratic Society and Students for Justice in Palestine — chanted “Free, free Palestine,” according to the Minnesota Daily, a campus newspaper. Anti-War Committee spokeswoman Meredith Aby-Keirstead told the Minnesota Daily, “I can’t just stand by and watch the university hire a war crimes apologist to come and speak here.”

In his speech, Halbertal argued that in fighting “asymmetric wars,” soldiers should err on the side of protecting noncombatants from being injured, the Post reported.