Colleges around the U.S. implored pro-Palestinian student protesters to clear out tent encampments with rising levels of urgency Monday, including an ultimatum from Columbia University for students to sign a form and leave the encampment by the afternoon or face suspension. Columbia activists defied the 2 p.m. deadline with chants, clapping and drumming from the encampment of more than 300 people. No officials appeared to enter the encampment, with at least 120 tents staying up as the deadline passed. The notice sent Monday by the Ivy League university in Manhattan to protesters in the encampment said that if they left by the deadline and signed a form committing to abide by university policies through June 2025 or an earlier graduation, they could finish the semester in good standing. If not, the letter said, they will be suspended, pending further investigation. Early protests at Columbia, where demonstrators set up tents in the center of the campus, sparked pro-Palestinian demonstrations across the country. Students and others have been sparring over the Israel-Hamas war and its mounting death toll. Many students are demanding their universities cut financial ties with Israel. The number of arrests at campuses nationwide is approaching 1,000.