KEENE, N.H. — Keene State College students quickly cleaned up from a chaotic weekend on Sunday after violent parties near the city’s annual pumpkin festival led to destruction, dozens of arrests and multiple injuries.

The parties around the school coincided with the Keene Pumpkin Festival, at which the community tries to set a world record of the largest number of carved and lighted jack-o-lanterns in one place. The violence prompted police in riot gear to use tear gas as they tried to control the crowds.

Sophomore Mallory Pearce, vice president of the student body, said she saw a car flipped over in a parking lot, another car being destroyed and people being pepper-sprayed.

“It got way out of hand. Everyone I talked to said, ‘I feel unsafe, I’m going home.’ They didn’t want to be part of the riot, and they couldn’t do anything to solve it,” she said. “I honestly did not feel safe.”

While Pearce was extremely disappointed in the violence, she said her faith was restored when about 200 volunteers showed up Sunday morning to clean up.

“We all recognize that we made a mistake, and we’re going to do better next year,” she said. “We’re not going to let this happen again.”

Gov. Maggie Hassan said in a statement Sunday night, “Like most New Hampshire citizens, I am outraged by the irresponsible, terrible actions that marred a New Hampshire tradition.”

She called on the state’s colleges and universities to “take swift action to hold students involved accountable.”

A police department log shows officers responded to 235 calls between 2:30 a.m. Friday and 3:30 a.m. Sunday and made at least 49 arrests. Not all were part of the disturbances, but at least 14 on Saturday and early Sunday appeared related to the unruly behavior. Most involved disorderly conduct or alcohol-related offenses.

WMUR-TV in Manchester showed video of a crowd overturning a car, people running from tear gas clouds, street signs being torn down and fires burning in the streets. Police also investigated reports of people throwing glass bottles and fireworks, jumping off a roof and banging on cars.

One group of young people threatened to beat up an elderly man, and another resident heard someone “threatening to kill officers,” according to the police log. About 20 injured people were taken to hospitals, Keene Fire Chief Mark Howard told New England Cable News.

Student body president Bobby Graham said he was disgusted by the destruction he saw and believes most of the perpetrators were not Keene State students.

“We are devoted to our community and very much engaged with our community,” he said.

Junior Brian Mazzola said most of the students in his apartment building decided to stay inside Saturday night after hearing about the brewing trouble.

“We could hear the helicopters circling around telling people to go inside,” he said.

Eammon Flynn, who was among about 30 students visiting for the weekend from Castleton College in Vermont, said he didn’t participate in any destruction but “went out and joined the mayhem.”

“The parties ended up being boring, and the riot ended up being wild,” he said. “It was fun to be around.”

College President Anne Huot said in an emailed statement that the festival has been promoted by others “as a destination for destructive and raucous behavior” and the college had tried working with the city and campus to prevent unruly conduct.

Officials are reviewing photos, videos, media coverage and social media postings to identify those responsible, Huot said, and the most serious offenders could be expelled.

“We care deeply about the citizens of Keene and our students, and we lament the impact of inexcusable behaviors on our city,” she said.

Ruth Sterling, whose company manages the festival, said the violence did not spill over into what she called “a truly beautiful event.”