Tensions on U.S. campus climbed further as standoffs between pro-Palestinian student protesters and universities continued Wednesday.

Hundreds of people encamped at Columbia University faced a deadline from the administration to clear out while dozens remained barricaded inside two buildings on a Northern California college campus.

Both are part of intensifying demonstrations over Israel’s war on Gaza by university students across the country demanding that schools cut financial ties to Israel and divest from companies that are enabling its monthslong conflict. Dozens have been arrested on charges of trespassing or disorderly conduct.

Columbia's President Nemat Shafik in a statement Tuesday set a midnight deadline to reach an agreement with students to clear the encampment, or "we will have to consider alternative options."

That deadline passed without news of an agreement. Videos show some protesters taking down their tents while others doubled down in speeches.

Rumors spread online that the deadline had been pushed to the morning, but the university declined to comment on whether that was true.

The heightened tension arrived the night before U.S. House Speaker Mike Johnson's trip to Columbia to visit with Jewish students and address antisemitism on college campuses.

Across the country, protesters at California State Polytechnic University, Humboldt, some 480 kilometers (300 miles) north of San Francisco, started using furniture, tents, chains and zip ties to block the building's entrances Monday evening.

"We are not afraid of you!" the protesters chanted before officers in riot gear pushed into them at the building's entrance, video shows. Student Peyton McKinzie said she was walking on campus Monday when she saw police grabbing one woman by the hair, and another student having their head bandaged for an injury.

"I think a lot of students are in shock about it," she told The Associated Press.

Three students have been arrested, according to a statement from Cal Poly Humboldt, which shut down the campus until Wednesday. An unknown number of students had occupied a second campus building Tuesday.

The upwelling of demonstrations has left universities struggling to balance campus safety with free speech rights. Many long tolerated the protests, which largely demanded that schools condemn Israel's assault on Gaza and divest from companies that sell weapons to Israel.

Now, universities are doling out more heavy-handed discipline, citing safety concerns as some Jewish students say criticism of Israel has veered into antisemitism.

Protests had been bubbling for months but kicked into a higher gear after more than 100 pro-Palestinian demonstrators who had camped out on Columbia’s upper Manhattan campus were arrested Thursday.

By late Monday at New York University, police said 133 protesters were taken into custody and all had been released with summonses to appear in court on disorderly conduct charges.

In Connecticut, police arrested 60 protesters – including 47 students – at Yale, after they refused to leave an encampment on a plaza at the center of campus.

Yale President Peter Salovey said protesters had declined an offer to end the demonstration and meet with trustees. After several warnings, school officials determined "the situation was no longer safe," so police cleared the encampment and made arrests.

In the Midwest on Tuesday, a demonstration at the center of the University of Michigan campus had grown to nearly 40 tents, and nine anti-war protesters at the University of Minnesota were arrested after police took down an encampment in front of the library. Hundreds rallied to the Minnesota campus in the afternoon to demand their release.

Harvard University in Massachusetts has tried to stay a step ahead of protests by locking most gates into its famed Harvard Yard and limiting access to those with school identification. The school has also posted signs that warn against setting up tents or tables on campus without permission.

Protesters at the University of California, Berkeley, which had an encampment of about 30 tents Tuesday, were also inspired by Columbia’s demonstrators, "who we consider to be the heart of the student movement," said law student Malak Afaneh.