Anti-Israel demonstrators have disrupted several commencement ceremonies at colleges across the United States as campus protests remain ongoing. Students and outside agitators opposed to the war in Gaza have demanded that colleges and universities fully divest from Israel and set up illegal encampments,

Some 30,000 graduates, family, and friends filled Harvard Yard Thursday for the university’s 373rd commencement, but the ceremony, steeped in tradition and pageantry, was disrupted when hundreds of students walked out about halfway through it in solidarity with 13 classmates who were barred from receiving diplomas because of their involvement in an unauthorized protest of Israel’s military campaign in the Gaza Strip.

Universities across the United States have adopted a number of tactics in recent weeks to prevent disruptions by pro-Palestinian protesters at graduation ceremonies.