SAO PAULO — A Brazilian woman whose short, pink dress caused a near riot at a private college led to her expulsion and transformed her into an Internet sensation now has permission to return to class.

Bandeirante University backed down Monday on its decision to expel 20-year-old Geisy Arruda following a flood of negative reaction in a nation where skimpy attire is common. Videos of students ridiculing her and making catcalls Oct. 22 turned up on the Web and drew attention to the event around the world.

Just hours after the Brazilian government demanded an explanation from the university, its dean released a statement saying he was reversing the school’s decision to expel Arruda.

The Education Ministry had given the university 10 days to clarify its reasoning for kicking out Arruda, who was forced to put on a professor’s white coat and was escorted away by police amid a hail of insults and curses from other students.

Arruda said just before the decision was issued that she was humiliated by the experience and was never warned by university officials that her dress was too racy, according to the private Agencia Estado news agency

“If a security guard or a professor had told me something I would have humbly returned home and changed my clothes,” she said, accompanied by seven lawyers at a packed press conference.

A video of the incident was posted on YouTube and quickly made headlines across Brazil. The university’s decision to expel the student Sunday prompted complaints from the national student union and the country’s minister in charge of women’s policy, among others.

The school is in a suburb of Sao Paulo, South America’s largest city, and prosecutors had said they would investigate what led to the decision to expel Arruda. The student had told reporters through one of her lawyers that she was going to sue the college so she could finish the semester.

The dean’s statement did not say why decision was being overturned.

Arruda and her lawyers could not be reached for comment on the school’s reversal, but in her interview ahead of the decision she said she wanted to return to school but was also scared about going back.

“I only want to go into the classroom, sit down, study and take tests,” she said.

Although Brazil is known for revealing clothing — especially in beach cities, where many bikinis are referred to locally as “dental floss” — most college students dress more modestly on campus, commonly in jeans and T-shirts.

The university published newspaper advertisements Sunday saying it expelled Arruda for disrespecting “ethical principles, academic dignity and morality.”

The ads also alleged Arruda acted in a provocative manner incompatible with the university’s environment.

University lawyer Decio Lencioni told Globo TV that the institution was merely following its rules.

“The problem is not her clothes,” he said. “It’s her behavior, her attitude.”

Lencioni and the university said Arruda even raised her dress and stopped to pose for photos the night she wore the short dress on campus. He said she also chose the longest way to get to class to attract the attention of more students.

Arruda vehemently denied the claim, saying, “It’s a big lie that I raised the dress,” Agencia Estado reported.

In Sunday’s ads, titled “Educational Responsibility,” the college said it had previously warned Arruda to change her behavior and decided to expel her after talking to students, staff and Arruda.

“I always dressed in a way that makes me feel good and that doesn’t offend anybody,” Arruda said during an interview with Brazil’s Globo TV. “I was always like that and was never recriminated by anybody.”

Civil police in the city of Sao Bernardo do Campo outside Sao Paulo, where the university is located, said they will investigate the students accused of heckling Arruda. The university said some will be temporarily suspended.

Arruda’s expulsion was condemned by Brazil’s national student union, the Brazilian BAR Association, and several other institutions.

The university’s original decision showed “intolerance and discrimination,” Brazil’s minister for women’s policy, Nilcea Freire, told the official Agencia Brasil news service.