Faculty members at the University of California, Berkeley are calling for a campus boycott when conservative speakers are scheduled to speak in the city later this month.

In an open letter, professors and staff members are calling for classes to be canceled, for buildings to be closed and for students not to be penalized for not showing up to campus from Sept. 24 to 27, SFGate.com reported.

The letter comes ahead of "Free Speech Week," a four-day event during which controversial figures including Ann Coulter, Milo Yiannopoulos and Stephen Bannon are expected to appear.

ADVERTISEMENT

The letter says signs point "towards an escalated and uncontrollable confrontation both on and off campus during these four days."

"Therefore, as faculty committed to the safety of our students and our campus, we are calling for a complete boycott of all classes and campus activities while these Alt-Right events are taking place at the very center of UC Berkeley’s campus," the letter says.

"As faculty we cannot ask students and staff to choose between risking their physical and mental safety in order to attend class or come to work in an environment of harassment, intimidation, violence, and militarized policing," it says.

The letter points specifically to "vulnerable populations," including young immigrants protected by the Deferred Action for Childhood Arrivals (DACA) program. It says these populations have already been harmed and "are reporting increased levels of fear and anxiety."

The letter makes clear faculty members are also worried about cyberbullying in addition to physical violence.

There are forms of speech "that are not protected under the First Amendment," the letter says.

"These include speech that presents imminent physical danger and speech that disrupts the university’s mission to educate," it continues.

"Milo, Coulter and Bannon do not come to educate; they and their followers come to humiliate and incite," the letter states.

The four-day event later this month is likely to draw large protests.

UC Berkeley was the scene of violent protests earlier this year, when Yiannopoulos was scheduled to speak at the school. His appearance was canceled.

The school increased security measures for conservative commentator Ben Shapiro’s speech last Thursday.