RIO DE JANEIRO -- Prosecutors in Rio de Janeiro launched an investigation Thursday into the fan violence surrounding the Copa Sudamericana final between local club Flamengo and Argentine team Independiente.
Clashes broke out on the night before Wednesday's match at Maracana Stadium, and continued until the early hours of Thursday. There was vandalism inside the stadium during the match and violence afterward, with more than 50 Flamengo supporters being detained over the two days.
The Rio prosecutor's office said in a statement it would be questioning officials at Brazil's football confederation, South American football's ruling body, CONMEBOL, and local police about the incidents.
The statement added that "a profound investigation of the facts is needed so we can identify and punish the criminals that disguised as fans to spread chaos, fear and disorder in society."
Flamengo drew the second-leg match 1-1, and lost the final 3-2 on aggregate. Copa Sudamericana is the second-most prestigious club competition in South American football.
Footage shows hundreds of Flamengo fans breaking into the Maracana before the match, dozens ripping seats off after the game, and others smashing the seats against various parts of the stadium.
Outside, cars were stopped by Flamengo fans and some had their windows smashed by rocks.
Police used tear gas and stun grenades to calm the situation.
Maracana administrators are still making estimates of the damage, which will be paid for by Flamengo.
Flamengo issued a statement Thursday, expressing its "indignation" at the events.
"We also want to show solidarity to all fans that, somehow, were affected by the savagery, violence and lack of citizenship of those that provoked chaos before and after the match," the club said.
Fans of the Rio club said they were provoked by Argentine supporters with racist gestures in the first leg of the final in Buenos Aires.
Several Argentine supporters were photographed making the same gestures in Rio.
Major Silvio Luiz, head of policing for the final, said Flamengo's handling of ticket sales was a "big part of the problem."
Luiz said: "The hosts did not control their sales properly, we could not check whether everyone coming to the stadium actually had a ticket."
Luiz indicated that he believed Flamengo should be punished for the incidents.
"Any club involved in a night like this needs to be held accountable," he said. "Otherwise fans will just keep doing this."