(CNN) -- Brazil's image as host of next year's FIFA World Cup took a hit Sunday when police fired tear gas at fans of rival football teams during a deciding league match in Santa Catarina state.
The fighting erupted in the stands just 10 minutes into the game Vasco da Gama needed to win to have a spot in the top league division.
Their rival, Atletico Paranaense, had scored the first goal when people in the stands started throwing punches and kicks. One man wielded a metal pipe and swung it toward a fallen fan. Security forces fired tear gas into the crowd.
The game was interrupted, and a helicopter landed on the field to take away an injured spectator.
Photos from the stadium show emergency workers carrying bloodied fans on stretchers.
Dr. Jose Eduardo Dias, one of the first doctors to arrive at the scene, said three people were critically injured.
"One was taken by the helicopter, and two others were taken on an ambulance," he told SporTV, a sister network of CNN affiliate TV Globo.
There were 80 private security guards inside the stadium when the fight broke out, Military Police Cmdr. Adilson Moreira told SporTV. Afterward, there were 160 government troops inside, he said.
Moreira said he didn't think heavier policing would have stopped the brawl.
"The fight could have broken out even if we were policing the area," he said. "It is the culture of the Brazilian fan. When they want to fight, they come to the stadium ready to fight. And unfortunately, even with our presence, this would have happened."
Vasco's goalkeeper Alessandro Oltramari told SporTV that he could see all the violence.
"This is very regrettable, especially since the country will be hosting the World Cup next year. It's regrettable when things like this happen," he said.
Tensions were high coming into the game between the Vasco and Atletico-PR teams in the final round of a high-profile tournament.
Days earlier, a post on a website for Atletico-PR's fans warned that violence was possible.
"Because of the high risk of fights and confrontations on the road and in regards to the high number of fans from rival teams coming to the last round of games," the website said, "we will not be selling tickets to women or children."
The game resumed after more than an hour, and Vasco lost 5-1.
CNN's Elwyn Lopez and Susanna Capelouto contributed to this report.