Scores of fans fought in the stands during today's match between Atlético Paranaense and Vasco da Gama at Arena Joinville in Santa Catarina, eventually turning into a riot.
According to a chart on globoesporte.com, the initial confrontation started at the edge of the Atlético Paranaense section closer to the Vasco section. It spilled over into the space between the sections, and eventually reached the part that Vasco occupied.
Three fans in critical condition were taken to the hospital. The fighting began at roughly the 17th minute of the match. Privately contracted security showed up a few minutes later to try and contain the riots, shooting tear gas.