Students protesting against the Israel-Gaza war continued to be met by police on Monday night, as a New York University encampment was cleared by the NYPD and students barricaded themselves inside a building at California State Polytechnic University at Humboldt, following dozens of arrests at Yale University.

University campuses across the country have seen an uptick in antiwar demonstrations in past days, including students moving into tents in protest encampments. Some of these, including at Columbia on Thursday and NYU on Monday night, were cleared by police called in at the request of the institutions.

College leaders are facing intense scrutiny over whether they are doing enough to protect students, faculty and staff against alleged antisemitism and other bias since the deadly Oct. 7 Hamas attack and subsequent conflict — even as they confront scathing criticism from those who say they’re denying students’ right to speak out and censoring political protests.

At California State Polytechnic University at Humboldt, the campus will be closed through Wednesday after student protesters barricaded themselves inside a building, Siemens Hall, the university said late Monday. The university urged people to stay away from the “dangerous and volatile situation” at the hall, and said it was “deeply concerned about the safety of the protesters,” urging them to “listen to directives from law enforcement … and to peacefully leave the building.”

In a Facebook post, the university added that in-person classes and activities would be “transitioning to remote where possible.”

A photo posted by National Students for Justice in Palestine showed the entry blocked with piled-up furniture.

Humboldt for Palestine, an activist group, posted on social media that students had “taken” the campus’s Siemens Hall, listing demands including that the university divest from any ties to Israel. It posted video of police appearing to push against the barricaded students and a statement that there had been arrests. When called late Monday, the University Police Department said it would answer questions “when the situation has de-escalated.”

In New York, the NYPD cleared a protest encampment centered at New York University’s Gould Plaza on Monday night at the request of the university, the NYPD and an NYU spokesperson said. Faculty were arrested as well as students, according to NYU Faculty for Justice in Palestine.

New York City Police Department Deputy Commissioner Kaz Daughtry said late Monday that the university had asked the police department to “clear Gould Plaza of individuals who were refusing to comply with repeated requests to disperse,” saying they had been described as “interfering with the safety and security of our community.”

“There is a pattern of behavior occurring on campuses across our nation, in which individuals attempt to occupy a space in defiance of school policy,” he added.

Videos on social media showed dozens of officers in tense confrontations with protesters. Some officers tossed tents, and others grappled with demonstrators. Videos also showed police loading people, whose hands were zip-tied behind their backs, onto correctional buses.

NYU spokesman John Beckman said that the university blocked access to the plaza where about 50 protesters were demonstrating “without authorization” Monday morning.

The barriers were breached early in the afternoon by additional protesters, “many of whom we believe were not affiliated with NYU,” who exhibited “disorderly, disruptive, and antagonizing behavior,” and refused to leave when told the protests would be disbanded, he said. The university then requested assistance from the NYPD, he said, adding there were “several antisemitic incidents reported.”

At Columbia University, where the latest wave of campus unrest began, the university sent out an email to staff and students on Monday requiring many classes at its Morningside main campus to be hybrid where possible for the rest of the semester. “Safety is our highest priority as we strive to support our students’ learning and all the required academic operations,” the university added in the email, seen by The Washington Post.

More than 100 demonstrators were arrested at Columbia when the university called in the NYPD to clear a pro-Palestinian protest encampment on Thursday, sparking solidarity demonstrations on other campuses.

Yale said 47 students were arrested at Beinecke Plaza on Monday and will be referred for disciplinary action, potentially including suspension. The school said it made repeated efforts over the weekend to talk to protesters, offered them meetings with trustees and warned of arrests before the Monday morning action. Police released the detained protesters.

“I was deeply saddened that the call for civil discourse and peaceful protest I issued was not heeded,” Yale President Peter Salovey said in a message to the campus community. Salovey noted that members of the Jewish, Muslim, Israeli, Arab, and Palestinian communities had “reported that the campus environment had become increasingly difficult.”

Tacey Hutten, a student protester at Yale who was arrested Monday, said in an interview: “Not only are we not deterred, we may even be more engaged now … we’re resolute. I’ve been involved in this struggle for a couple of months now and plan to be for the rest of my life.”

Meanwhile, other campuses also are contending with increasingly aggressive campus activism. A group of student protesters at Pomona College in California was arrested earlier this month after storming the president’s office. At the University of California at Berkeley in February, protesters broke windows and a door while disrupting a talk given by an Israeli lawyer.