South American football confederation Conmebol says it condemns "any acts of violence and racism" around the Copa Libertadores final.

Police said two Argentine men and one Brazilian were detained following a clash at a Copacabana beach fan fest.

The final takes place on Saturday.

"Conmebol calls on the fans of Boca Juniors and Fluminense to share together the moments of joy and celebration that our football gives us," said South America's football confederation.

"The values of the sport we are most passionate about should inspire peaceful and harmonious behaviour.

"We therefore repudiate any acts of violence and racism that may occur in the context of the final."

Fluminense will be playing at their home ground of the Maracana Stadium as they try to win the Copa Libertadores for the first time.

Boca Juniors have won the competition six times.