PORTLAND, Ore. (NewsNation) — Police cleared out Portland State University’s Millar Library Thursday, days after protesters barricaded themselves inside the building.

Most protesters left the library before the Portland Police Bureau could arrest those who remained behind barricades. Police said there were 12 people arrested, including four students.

Protesters were seen trying to evade police officers on campus. The university also issued a shelter-in-place order for Montgomery and Blackstone Halls, though it’s unclear if that is in connection to the protests. 

NewsNation local affiliate KOIN captured video of Portland police making their way into the building around 9 a.m. armed with 40mm “less-lethal” launchers. After the library was emptied around 10:30 am, some protesters then took to the area outside of the university.

While the police bureau previously said they did not plan to use tear gas on protestors inside the building, chemical munitions appeared to be deployed in the open air once protestors left PSU, according to KOIN.

According to a PPB news release, a group of pro-Palestinian protesters unlawfully entered the university’s library after leaving a peaceful campus protest on Monday.

The occupation was one of many encampments at college campuses nationwide as protesters called for a ceasefire in Gaza. The group has since occupied the building, ignoring all warnings to leave campus property.

“Portland Police personnel swear an oath to protect constitutional First Amendment rights and we are committed to ensuring safety for all Portlanders who exercise their lawful right to assemble and express themselves, but as a city, we will not allow criminal behavior that disrupts our community,” Portland Police Chief Bob Day said. “We will pursue all efforts at de-escalation, but make no mistake: PPB will take appropriate action to do our part to hold individuals and groups accountable for their criminal conduct. I have the utmost faith that our PPB membership will continue to perform in the most professional manner.”

Police closed streets around the campus due to the operation.

Inside look at Millar Library

NewsNation’s affiliate KOIN was able to go inside Millar Library on Tuesday, where the crew observed graffiti, broken glass and smashed computers, along with blocked emergency exits. However, the books in the library appeared to be untouched.

They spray-painted graffiti on inside walls and knocked over or piled furniture to create barricades.

“PSU ALERT: Millar Library is closed. NO ONE is authorized to be in the library. Anyone remaining is committing criminal trespass,” the university posted to X, formerly known as Twitter.

University President Ann Cudd said in a statement late Wednesday that classes would resume Thursday, but Portland State said on social media Thursday morning that the campus would instead be closed because of the police activity.

Cudd said Wednesday that about 50 protesters had vacated the Millar Library after administrators promised not to seek criminal charges, expulsion or other discipline against participants who left peacefully, but others — including nonstudents — remained. Portland police also said Thursday that 15 police vehicles were damaged by arson overnight; it was not immediately clear if that was related to the protest.

Politicians condemn ‘criminal behavior’

Multnomah County District Attorney Mike Schmidt, Mayor Ted Wheeler, Cudd and Day addressed the situation Tuesday evening, condemning any criminal behavior.

“Damaging property, making threats, and perpetrating violence are not acceptable, meaningful, or productive ways to make a point. These are destructive behaviors that harm community members and local businesses,” Schmidt posted to X.

Despite rumors that Schmidt’s DA officer would not pursue any charges, the PPB said Schmidt offered his team’s full support and will ensure cases are effectively investigated and prosecuted when appropriate.

Universities across the U.S. have been grappling with how to deal with encampments as commencement ceremonies approach, with some continuing negotiations and others turning to force and ultimatums that have resulted in clashes with police.

The number of arrests at campuses nationwide has exceeded 1,000 as the final days of class wrap up.

The outcry is forcing colleges to reckon with their financial ties to Israel as well as their support for free speech. Some Jewish students say the protests have veered into antisemitism and made them afraid to set foot on campus.

Protesters have said, though, that those being antisemitic do not represent them and pointed out that many Jewish students are joining them in their cause.

Some student demonstrators held signs saying “Jews for Free Palestine” or “Jews for Palestine,” while pictures on social media circulated of Passover seders being held at the encampments.

NewsNation affiliate KOIN contributed to this report.