Updated

A California state university has indefinitely suspended fraternities and sororities after photos surfaced showing a fraternity member in blackface and others dressed up as gang members.

The move at California Polytechnic State University was announced Tuesday by school President Jeffrey Armstrong, who said in a lengthy letter to the campus community that it has been gut-wrenching "to witness the hurt so many have felt and continue to feel."

The suspension covers "all Panhellenic and Interfraternity Council fraternities and sororities," the letter said.

Last week, the university suspended the Lambda Chi Alpha fraternity after photos emerged on social media of one member wearing blackface and others posing and dressing up like gang members.

The university took the broader action after learning of another instance of "racial profiling and cultural appropriation" at the Sigma Nu fraternity, Armstrong wrote.

Photos showing three Sigma Nu members dressed as gang members emerged on social media Tuesday.

Hundreds of students at the school protested and held an emergency town hall after the Lambda Chi Alpha photos emerged.

"If Greek Life is to remain at Cal Poly, these students must re-invent their organizations and activities so they add value to our campus community and foster a culture of inclusion instead of undermining it," Armstrong said.

In addition to the suspension, Armstrong said the university is meeting with and fielding ideas from minority students about improving campus culture, hiring a specialist on diversity and inclusion, and requiring training on implicit bias for all campus hiring committees.

About the individual students pictured in blackface or as gang members, Armstrong said constitutional protections of free speech bar the university from punishing them individually.

"There are times when values conflict — when we are torn between a duty to oppose hate and a duty to protect free speech," he said. "As individuals, each of us can choose which value to put first, but as a state university, the law makes that choice for us. We cannot ban hurtful speech and expression on campus; we can only overcome it."

Cal Poly spokesman Matt Lazier said in a statement Wednesday that the suspension also involves wider problems that Greek organizations have been involved in over the past few years.

"These problems have included racially charged and insensitive events, sexual assaults, hazing and alcohol-related deaths, and violations of the university's code of conduct regarding hosting social events," he said.

He added that the suspension isn't intended to punish those in Greek organizations who've done nothing wrong, or even any particular organization.

Rather, the message is that "Greek culture as a whole is broken."

"Too many people have been hurt by the actions and by the failures to act of Greek organizations at Cal Poly," Lazier said. "This stops now."

The suspension does not apply to Cal Poly's cultural fraternities and sororities, which are governed separately by the United Sororities and Fraternities Council.