New York City police arrested at least 108 people Thursday during a pro-Palestinian protest on Columbia University's campus after the university's president requested their removal, per Mayor Eric Adams.

Why it matters: The confrontation comes a day after Columbia president Nemat "Minouche" Shafik and other university leaders testified to Congress over the campus climate and antisemitism since the start of the Israel-Hamas war.

• More than 100 people occupied the campus' South Lawn when NYPD was involved, Shafik said in her request to deputy commissioner Michael Gerber. Adams said the protesters were there for more than 30 hours.
• Those who were taken into custody were issued summonses for trespassing, officials said during an evening news conference. Two people were also charged with obstruction of governmental administration.
• The police presence led to an impromptu protest in support of those who were detained.

Catch up quick: A new policy was instituted in February that approved specific locations for demonstrations, which require advanced notice.

• Protestors began setting up an encampment on the university's campus before dawn on Wednesday, Shafik said. They were calling for the school's divestment from economic and academic stakes in Israel.
• During Wednesday's congressional hearing, Shafik said the university would continue to crack down on unauthorized protests.

State of play: The university notified students on Wednesday night that those who remained in the encampment would face suspension, Shafik said.

• "We also tried through a number of channels to engage with their concerns and offered to continue discussions if they agreed to disperse," she wrote in a letter to the campus community.
• A university spokesperson said the school is still identifying those who participated in the protests and will send them formal notifications.
• "Students have a right to free speech. They do not have the right to violate university policies and disrupt learning on campus," Adams said during the news conference.

Zoom in: Isra Hirsi, Rep. Ilhan Omar's daughter, was suspended from Barnard College over her activism, she said on X.

• Police later confirmed she was among the arrested protesters, and was issued a summons for trespassing.
• "I have never been reprimanded or received any disciplinary warnings," Hirsi said. "I just received notice that I am 1 of 3 students suspended for standing in solidarity with Palestinians facing a genocide."
• Hirsi was named to Fortune's 40 under 40 in Government and Politics list for her political advocacy and founding the U.S. Youth Climate Strike.
• Omar questioned Shafik about the school's protection of Muslim and pro-Palestinian students during the hearing, which was centered on antisemitism.

Axios' Sareen Habeshian contributed to this report.

Go deeper: "Moral crisis on our campus": Columbia leaders testify to Congress on antisemitism