Players brawled on the pitch during one Brazilian championship derby and fans clashed with riot police on the terraces during another on Sunday.
The Internacional-Gremio match in Porto Alegre was marred by ugly scenes just before halftime following a tackle by Internacional defender Edinho on Gremio playmaker Tcheco.
The two became entangled and others immediately joined in followed by members of the two substitutes' benches.
Officials struggled to control the situation as players pushed, threatened and argued with each other, interrupting the match for nearly five minutes.
When the situation calmed, Edinho and Tcheco were sent off.
Internacional, inspired by Argentine midfielder Andres D'Alessandro, won 4-1, with all the goals coming in the first half, and enjoyed the added bonus of knocking their arch-rivals off the top of the table.
D'Alessandro rifled Internacional in front after four minutes and provided the crosses for Indio and Nilmar to score two more in a five-minute spell before halftime.
In between, Tcheco equalized for Gremio with an individual goal and Alex put Internacional back in front in the 28th minute.
The crowd trouble happened in Curitiba when fans of visiting Atletico Paranaense fought with police on the terraces at the Couto Pereira stadium during the game against Coritiba.
Television pictures showed riot police chasing fans on the terraces with Alsatian dogs and truncheons.
Media reports said the trouble began when a Coritiba fan hurled a firecracker towards the Atletico supporters.
(Xinhua News Agency September 29, 2008)