Police were in a tense standoff with Gaza war protesters Monday night at Cal Poly Humboldt, which has been closed for nearly a week with some students occupying campus buildings.

Authorities told more than 100 protesters that they had to leave, but most remained.

Demonstrators, some wearing goggles, helmets and makeshift shields, spent the night chanting and playing music. At 9 p.m., a police vehicle drove by announce they could be subject to rubber bullets and chemical agents.

Some faculty members, who were told by the university that they should not enter campus, massed just outside, observing.

Protesters have occuped Siemens Hall, an academic and administration building, and another building.

Last week, three students were arrested after demonstrators occupied Siemens Hall and clashed with law enforcement officers wearing helmets and riot shields who descended on campus.

According to the university, protesters blocked entrances and elevators with tents and in some locations shut doors using chains and zip ties, violating fire codes and “creating extreme safety hazards for those inside.”

Campus administrators said there were reports that protesters broke into the president’s office and accessed sensitive materials — allegations the protesters deny.

Officials said “hateful graffiti” also has been painted on university property in recent days.