Boca Juniors and Fluminense urge fans to behave ahead of Libertadores final
Two Argentines and one Brazilian were arrested on Thursday by local police after security officers intervened following a clash between supporters at the fan fest on Copacabana beach.
The South American Football Confederation (CONMEBOL) condemned the violence and held a meeting on Friday chaired by its president Alejandro Dominguez with leaders of the clubs, the Argentine FA (AFA) and Brazilian Football Confederation (CBF).
"It is very important that there is an atmosphere of peace between the fans that unites them so that people can enjoy the beautiful festival of football at the Maracana stadium," said Fluminense president Mario Bittencourt.
Boca chief Jorge Amor Ameal added: "This is not a war, it's a football match, a celebration of Latin American football. We love the Brazilian people very much but some violent people want to change that.
"We ask people to please respect our opponents."
Security measures for the match include liaison between local and state police plus a tightening of procedures for fans entering the stadium and reinforcement of the sections assigned to each team's supporters and the perimeter around the Maracana.
The Libertadores final, South America's equivalent of Europe's Champions League, sees Boca seeking a seventh title and hosts Fluminense hoping to lift their first continental trophy after losing to Ecuador's Liga de Quito in the 2008 final.