Standoffs between pro-Palestinian student protesters and universities are growing increasingly tense on both coasts of the US. In New York, Columbia University's administration has given hundreds of demonstrators a deadline to clear a large campsite. Meanwhile, dozens of students remained barricaded inside two buildings on a Northern California campus. Both developing incidents are part of intensifying student demonstrations against Israel's war with Hamas, leading to dozens of arrests on charges of trespassing or disorderly conduct. Columbia's president, Minouche Shafik, yesterday set a midnight deadline to reach an agreement with students to clear the camp, saying that if they did not, the university leadership would “consider alternative options.” The deadline passed without news of an agreement.  Videos show some protesters taking down their tents, but others doubled down in speeches. The rise in tensions came the night before US House Speaker Mike Johnson's trip to Columbia to visit with Jewish students and address the issue of antisemitism on college campuses. Across the country, protesters at California State Polytechnic University, Humboldt, started using furniture, tents, chains and zip ties to block the building's entrances. The defiance was less expected in one of California's more conservative regions, some 480km north of San Francisco. Video showed protesters chanting “We are not afraid of you!” before officers in riot gear pushed into them at the building's entrance. The university says three students have been arrested, and the campus was shut until Wednesday. An unknown number of students occupied a second campus building  on Tuesday. Delicate balance The upwelling of demonstrations has left universities struggling to balance campus safety with free speech rights. Many institutions have so far tolerated the protests, which have largely demanded that schools condemn Israel's assault on Gaza and divest from companies that sell weapons to Israel. But some universities are now doling out more heavy-handed discipline, citing safety threats to Jewish students and faculty – some of whom say protesters' 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 centre of campus. In the Midwest on Tuesday, a demonstration at the centre 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. Campus protests began after Hamas' deadly attack on southern Israel, when militants killed about 1,200 people, most of them civilians, and took roughly 250 hostages. In the ensuing war, Israel has killed more than 34,000 Palestinians in the Gaza Strip, according to the local health ministry, which doesn't distinguish between combatants and non-combatants but says at least two-thirds of the dead are children and women.