RIO DE JANEIRO (AFP) - Rio de Janeiro riot police arrested dozens of Flamengo football fans on Wednesday, when they used fireworks to attack hotels housing members of Argentinian team Independiente ahead of a regional cup final.

Flamengo fans "shot fireworks and rockets" at a Hilton in Barra de Tijuca neighbourhood, where part of the Independiente de Argentina team was based, the Rio state security office said.

Rampaging fans also let off long, deafening barrages of bangers outside another hotel used by Independiente next to the popular Copacabana beach in the early hours of the morning.

Forty eight people were arrested, officials said, and fireworks, cobblestones and bottles were confiscated.

The teams will play the final of the Copa Sudamericana in a packed Maracana stadium in Rio later on Wednesday.

Independiente fans gave Flamengo supporters a rowdy reception during the away leg, which the Argentinian team won 2-1, and the Brazilians had vowed to respond in kind during the decisive return match.