On a balmy Saturday in Ann Arbor, Mich., thousands of graduates in caps and gowns filed into the biggest stadium in the country for the University of Michigan’s graduation ceremony.

As tens of thousands of spectators found their seats in the packed Michigan Stadium, planes with dueling messages circled overhead: one with a banner that read, “We stand with Israel. Jewish lives matter,” and another with the message, “Divest from Israel now! Free Palestine!”

Then, dozens of pro-Palestinian graduates draped in flags, kaffiyeh and graduation caps marched down the center aisle toward the stage. They chanted, “Regents, regents, you can’t hide! You are funding genocide!” calling for the university to divest from investments that have benefited Israel.

At least a dozen officers from the Michigan State Police quickly followed to block the parade from making it to the stage, urging protesters to retreat to the back of the graduates section.

As the chants reverberated throughout the stadium and demonstrators talked to the police, some students got up from their seats and joined in, disobeying police officers who told them to sit down.

But other students — some with the Star of David on their caps — were enraged by the disruption and demanded that the protesters be kicked out. “You’re ruining our graduation!” one yelled. Some patrons in private boxes hung Israeli flags from their seats.

Once the demonstrators moved to the back of the ceremony, tensions simmered, and the protest remained peaceful. The chants never stopped — though how audible and distracting it was might have depended on where people sat in the stadium — but the audience returned their attention to the stage as the ceremony carried on.

Jonathan Ellis contributed reporting.