Some students walked out of their classes shortly after 10 a.m. to call on a university divestment of funds from Israel.
The rally was said to be mostly peaceful. AIR7 was over the scene as the group blocked a street on the west side of the campus, but there was little police presence visible.
At one point around 11 a.m., the pro-Palestinian protesters stormed Carnegie Hall and blocked many of the doors. Some students said the only way they could leave the building was to climb out of a window.
There were no reports of violence or arrests.
The college released a statement saying Carnegie Hall was closed, and that anyone who remains inside is trespassing:
What started as a peaceful protest this morning has now turned into a subset of individuals currently taking over Carnegie Hall and disrupting academic continuity.
Carnegie Hall is now closed, and all individuals should leave that building.
We do not believe there is a physical threat, however, please stay away from Carnegie and its immediate surrounding area, to ensure everyone's safety.
We will not permit the presence of masked, unidentified individuals on our campus refusing to show identification when asked. Nor will we stand for the takeover of buildings and the disruption of academic continuity - all of which happened today. Anyone involved in this disruption is subject to disciplinary action.
To ensure academic continuity, students scheduled to have class in Carnegie Hall this afternoon should reach out to their professors for details on plans for their classes.
We ask that all faculty consider and determine what is the best choice for your class. Please keep in mind the importance of academic continuity and the need to preserve a learning environment free of discrimination or hostility. Please consider thoroughly the needs of all your students in making any decision around your classroom activity.
We uphold the right to free speech and to protest within the lines of our long-established Claremont Colleges demonstration policy. As always, peaceful protest is allowed within demonstration policy. This action goes beyond policy.
Earlier this year, pro-Palestinian protesters set up an encampment on the Pomona College graduation stage. The group vowed to remain in place unless the college committed to divest from Israeli-tied companies and weapons manufacturers. That forced the college to move the commencement ceremony.
Pomona College moves commencement after protesters set up encampment on graduation stage
That came about a month after 19 students were arrested while taking part in a sit-in at the university president's office.
City News Service contributed to this report.