At least 900 protesters have been arrested at pro-Palestinian demonstrations on college campuses in the last 10 days, according to a Washington Post tally, the largest police response to campus activism in years and one that experts say poses myriad potential challenges for law enforcement agencies.

Mass demonstrations on campuses ranged from peaceful sit-ins on sun-soaked grassy malls to vitriolic confrontations with counterprotesters. To remove protesters calling for a cease-fire in the Israel-Gaza war and universities to divest from Israeli financial interests, some administrators turned to police, pointing to numerous reports of hate, antisemitic speech and violence that marred some demonstrations.