Protests and arrests spread across some of America’s most influential universities on Monday, as administrators struggled to defuse tensions on campuses over pro-Palestinian demonstrations on Monday.

Nearly 50 people were arrested at Yale University in New Haven, Conn., on Monday morning, following the arrests last week of more than 100 protesters at Columbia University in New York City. The arrests unleashed a wave of activism across other campuses, including M.I.T., the University of Michigan and Stanford University, as protesters sought their universities’ divestment from companies with ties to Israel and a cease-fire in Israel’s war in Gaza.

The flurry of protests has presented a steep challenge for university leaders, as some Jewish students say they have faced harassment and antisemitic comments. Early Monday morning, Columbia announced a same-day shift to online classes because of the protests. Barnard College, across the street, followed suit hours later.

Here are scenes from the protests.