SAO PAOLO — A band’s pyrotechnic display at a nightclub in southern Brazil early Sunday morning turned deadly, killing 233 and injuring dozens when a flare set the building ablaze, according to police and televised reports.

The nightclub, called Kiss, was hosting a party for a group of students from the Federal University of Santa Maria who were celebrating the end of their summer break when the fire broke out at about 2 a.m. Sunday. Videos posted on YouTube showed a smoke-filled scene as firefighters and shirtless club-goers dragged people from the building. Hundreds crowded the streets, sitting or lying on the pavement.

“People were screaming and trying to run to the exit,” Luciene Louzeiro, a survivor of the incident who was near the stage when the fire started, said in a televised interview with local news service O Globo. “It was horrible. I’ve never seen anything like it.”

Most of the victims at the club located in Santa Maria, which is home to a number of universities, were students who died from smoke inhalation, Andre Diefenbach, an official with the municipality’s police department, said in a telephone interview. Some may have perished as they attempted to reach the club’s doors, while others died after running into the bathroom, he said. Some of the club’s security guards may have initially stopped people from leaving the premises before paying, he said.

One video shot amid the chaotic scene showed several bodies on the ground outside the club. Medical personnel checked them for signs of life and carted them off on stretchers. A woman can be heard shrieking in the background.

The incident prompted President Dilma Rousseff to cut short her participation in a summit of Latin American and European leaders in Santiago so she could return to Brazil. The president, who lived for more than a decade in the state of Rio Grande do Sul, where Santa Maria is located, arrived in the city Sunday to visit the scene of the fire and console families of victims, according to the presidential website.

“It is a tragedy for us all,” Rousseff, choking back tears, said to reporters in Santiago earlier Sunday before returning to Brazil. “Who needs me today is the Brazilian people and that’s where I have to be.”

Rousseff has declared three days of mourning for the victims of the fire, Agencia Brasil reported without saying where it got the information.

The dead were transported to a local gymnasium, where families are identifying the victims, Major Cleberson Bastianello of Rio Grande do Sul’s military police said in a phone interview. Another 92 wounded have been hospitalized, he said.

Victims in critical condition were being airlifted to the nearby city of Porto Alegre for treatment, while families are also receiving psychological support. The majority of the wounded are being treated for smoke inhalation, the government said, citing Health Minister Alexandre Padilha.

There may have been as many as 900 people in the club, which has a capacity of about 2,000 people, said Diefenbach, the police official. Some security guards have been accused of not letting people leave before paying, Diefenbach said. In Brazil, club-goers normally pay for their drinks on their way out.

“I saw black smoke coming in my direction,” Fernanda Bona, who managed to escape the blaze, said in a televised interview with O Globo. “Hundreds and hundreds of people were going for the same door, but because this area was so near the door not many people were able to leave. When I ran out, I didn’t have any idea how bad it was going to be. Ten minutes later I saw people, bodies, more and more people burnt, unable to walk.”

The band Gurizada Fandangueira was playing at the time the fire started, and one of its members is among the victims, O Globo reported, citing the band’s drummer, Eliel de Lima. Also scheduled to play last night were DJ Bolinha, DJ Sandro Cidade DJ Juliano Paim and Pimenta e seus Comparsas, according to the club’s website.

The incident may be the worst fire in Brazil’s history since 1961, when 503 people died at a circus in the state of Rio de Janeiro, the newspaper Folha de S. Paulo said Sunday. Brazil is seeking to improve its safety record before the 2014 World Cup.

In 2004, a blaze at a rock concert in a Buenos Aires killed 193, and the nightclub owner was convicted of manslaughter. In the U.S., fireworks led to the death of 100 people at a club in Warwick, R.I., in 2003 when a pyrotechnics malfunction ignited foam used as soundproofing on the club’s walls.

Santa Maria, with more than 250,000 residents, is about 500 miles southwest of Sao Paulo city. It has a young population because of its large number of universities.

“I hope that God gives us strength and courage to help those who most need our solidarity and compassion at this time,” Federal Deputy Paulo Pimenta, who is from Santa Maria and represents the region for the governing Workers Party, wrote in a message on his Twitter page.