A MHERST — The new academic year was supposed to be a triumphant return to full-time campus life after the trials of pandemic-era restrictions. Instead, the state’s leading public university is in an uproar over racist hate and sexual assault on campus, problems that students say the school has allowed to fester for decades.

In September alone, there were seven incidents of bias reported to the University of Massachusetts Amherst and nine reports of sexual assault, three of which allegedly occurred in just the first few weeks of the school year.

Two incidents in particular have galvanized students. First, a crude and racist e-mail landed in the inboxes of Black student organization members; then, in late September, an anonymous accusation surfaced of a sexual assault at a fraternity.

Frustration among students has boiled over into heated demonstrations, days-long sit-ins, and insistent calls for decisive action from the administration. Students say racism and sexual assault have been allowed to poison the culture at UMass for too long, and they are demanding change.

Racism is “something that’s very real, and it happens very often, and it’s something that’s not talked about a lot,” said Jordan O’Hare Gibson, a junior biology major from Lexington who is Black.

Only about 5 percent of the institution’s 24,000 undergraduates are Black, according to university statistics, and 19 percent are people of color.

The university’s administration maintains a long list of reports of racist, antisemitic, homophobic, and transphobic verbal harassment, graffiti and other offenses. Those reported this fall, according to a university website, include anti-Black and antisemitic symbols drawn on a student’s car, an anti-Black sexist epithet written in a dormitory, and racial profiling by staff. The university lists another 76 incidents dating to the fall of 2018.

In an interview, Chancellor Kumble R. Subbaswamy expressed concern about the incidents, but pushed back on the notion that there is a systemic issue with the culture at UMass.

Of the racist e-mail, Subbaswamy said, “All it takes is one really deranged or highly, highly, frustrated individual to throw a hand grenade like this.”

But to Lezine Swan, a fourth-year architecture major, the angry demands from students seem overdue.

When Swan’s father, Talbert Swan, was a student at UMass Amherst in the 1980s, he grew accustomed to the racial slurs hurled at him and other Black students on campus. A white student punched him in the face during the infamously racist World Series brawl in 1986. Another night, while attending a party in the student union ballroom, he was pulled outside by campus police and held at gunpoint.

“Put your hands up or you’ll die in the night,” Swan’s father vividly recalls campus officers saying, insisting he fit the description of a criminal suspect.

More than three decades later, in 2018, Swan was only a few weeks into his freshman year when someone scrawled a racist death threat on a mirror of a bathroom in the Melville dorm. “Hang Melville” and the n-word, the message read.

So it was with disgust, but not surprise, that Swan read the racist and threatening e-mail sent to him and members of other Black student groups on campus last month. The e-mail expressed hateful anti-Black sentiments, accused Black students of being admitted only to meet diversity quotas, and promoted racial sterilization.

“Between the time that my father attended school [and now], the hatred has not dissipated one bit,” said Swan, a member of Iota Phi Theta, a historically Black fraternity.

The racist e-mail surfaced around the same time that an anonymous allegation of sexual assault against members of Theta Chi, a campus fraternity, circulated on social media. Those allegations sparked massive protests that started two weeks ago and have continued off and on since. The university says it has not received any complaints of sexual misconduct at that fraternity during the weekend in question.

Theta Chi did not respond to a request for comment Saturday.

But in a statement issued Sept. 20, the day after the first large protest outside the fraternity, the international headquarters of Theta Chi said it was unaware of any formal complaints filed against the chapter or its members. The headquarters urged any agency that received reports of misconduct to review them immediately and said threats or actions that harm the chapter will be reported to law enforcement and the university

“These allegations have caused an uproar of violence on campus and Theta Chi asks local law enforcement to continue to provide safety for all students,” Theta Chi said.

The growing tensions prompted some students to publicly air allegations of other sexual assaults at UMass fraternities and to accuse the university of inaction.

Some students say they see the licentiousness and elitism often associated with Greek life as contributing to an environment where both racism and sexual misconduct can thrive.

Anika Nayak, who is Asian American, spent her first year studying remotely from her home in Somerville. She came to Amherst this fall looking forward to finally experiencing campus life, but living here has put her on edge.

“There is definitely an overarching sense of fear for women on campus, especially because there’s such a frat culture here,” she said. “Walking around here at night can be scary.”

Student activists have a range of demands, from better communication and visibility on the part of the administration to abolishing fraternities altogether. Some want the university to adopt what is known as the Survivors Bill of Rights, which would suspend Greek life chapters involved in sexual allegations, open criminal investigations, and expel parties found guilty of sexual misconduct.

The UMass Interfraternity Council issued a statement on Sept. 20 saying it was “devastated by the presence of sexual assault and harassment within the UMass community.” The council’s executive board said it supports the Survivors Bill of Rights, and that it had taken steps to prevent sexual assault and would “continue the effort to eradicate these egregious behaviors from our campus.”

But protesters aren’t satisfied with such statements. On campus Saturday, a group of about 20 students gathered outside a university ballroom where Subbaswamy had been set to welcome families to parents weekend.

They held signs with messages that said “UMass isn’t safe for your daughter,” and “Swamy protects rapists.”

The student protesters were not allowed into the ballroom and, in a last-minute schedule change, the chancellor did not speak. As parents left the forum, protesters distributed flyers that asked people to contact the administration to express their concern.

Leaving the forum, Bob Matthews and his wife, Paula-Ann, said they are troubled by the incidents of sexual assault that the protesters spoke to them about. Their daughter is Chinese, they said, and they are also concerned about anti-Asian racism. They called on administrators to be more responsive to both issues.

“This is not a joke, this is serious business,” Matthews said.

Because of the pandemic, the weekend was also the first time that the parents of many second-year students had visited their children at college. Crimson decorations dotted the campus as families strolled to barbecues, performances, and open houses.

Down the street from the ballroom protest, Theta Chi members were setting up a beer pong table behind their brick fraternity house. “The Boys are Back in Town” blasted over loudspeakers.

Subbaswamy met for two hours last week with about 200 students and promised to adopt a version of the Survivors Bill of Rights, as well as to conduct a review of sexual assaults going back seven years, according to the Daily Collegian.

In an interview with the Globe, Subbaswamy said the university has become more diverse, an important step to creating a more inclusive culture, and uses its academic curriculum and residential life programming to teach students how to respect one another.

“I absolutely agree that it’s our responsibility as an educational institution to instill that level of understanding, as well as, if nothing else ... dignity and respect,” he said. “But, again, if somebody harbors deep racist feelings, then it’s hard to deal with that.”

Some students, however, say the institution should work harder to root out racism, and to make sure open displays of hate don’t go unaddressed. Like Swan, Zachary Steward was also a freshman at UMass and lived in the Melville dormitory when the death threat appeared on the bathroom mirror in 2018. Steward said university officials promised to investigate, but warned that “things take time.”

The university never followed up with him about the results of the investigation, he said.

“It showed me first and foremost that this university does not care about me,” said Steward, who is Black, in a phone interview last week. “Every year, something like this happens, and nothing gets done.”

Black students point to the long gap between Sept. 8, when some first began receiving the racist e-mail, according to the Amherst Wire, the campus’s student magazine, and Sept. 23, when students received the first communication from the university about the incident.

The letter, from Nefertiti Walker, vice chancellor for diversity, equity, and inclusion, condemned the e-mail and outlined steps the university is taking to support Black students and investigate the e-mail, including hiring a cybersecurity firm to trace the sender.

In an interview last week, Walker described additional efforts she and her staff are taking to reform the larger culture at UMass. Unfortunately, she said, there are no easy fixes.

“UMass and all college campuses are a microcosm of what’s happening in society,” she said. “The idea of eradicating racism on a college campus is in some ways very similar and mirrors how we would eradicate racism in America. ... And that’s a question that hasn’t been resolved by anyone.”

Her most pressing responsibility, Walker said, is to make sure Black students “feel supported, loved, and like they can be their complete self” at UMass. To that end, she is focused on increasing the number of Black students on campus and building a campus infrastructure that supports a thriving Black community.

She is working on several initiatives to create systemic change across the university in terms of curriculum, programs, hiring, and training.

Walker said the university encourages Black students to utilize university counseling services. On Tuesday night, the university will host a forum for Black students and administrators, and it will also support students’ efforts to host their own events, she said.

But Black student groups are frustrated at what they see as a lack of urgency. Several held an event on Thursday night for Black students to discuss the recent events in a safe space. (Walker said she and other administrators attended, sitting in the back to listen.)

“We are angry. We are hurt. We are tired,” the Black Student Union said this week in a post on Instagram, where much organizing and communication has taken place. The union also expressed “displeasure and outrage at the lack of response” from the university.

The Alpha Kappa Chapter of the Alpha Phi Alpha Fraternity, a historically Black fraternity, sent a letter to the administration last week that expressed similar anger and disappointment at the “vile and reprehensible” racist e-mail.

The organization made four demands of administrators: support for the Black Student Union; more funding for student organizations; hiring more diverse faculty and staff, including an ombudsman for minority affairs; and building a better network of support for Black students, including seminars for first-years and “check-ins” with the administration.

“We are extremely disappointed by the lack of swift and decisive action by the administration in response to this act of aggression.”

Lori Patton Davis, a professor at Ohio State University who specializes in higher education and student affairs, said that even as they offer support for Black students, institutions need to address the behavior of white students.

She also encouraged students to save the written statements of administrators, to hold them accountable down the line.

Julia Carlin can be reached at julia.carlin@globe.com.

Work at Boston Globe Media