SAO PAULO -- Brazilian police have detained six people after a confrontation that left a 21-year-old football fan dead this weekend, marking the third death involving rival supporter groups in Sao Paulo this year.
Authorities said Monday that the six men will be interrogated to explain their participation in the fighting that took place on a major highway just hours before the Brazilian league game between Palmeiras and Santos on Sunday at the Pacaembu Stadium.
Four people remained hospitalized, including one with a gunshot wound. Their condition was not immediately released, though local media reported the injuries were not life-threatening.
Police said the man who died was run over by a car after he and other Palmeiras fans went onto the highway to try to ambush two buses carrying Santos supporters.
Palmeiras fans tried to block the buses and used rocks and pieces of wood in the attack. Authorities believe a Santos supporter shot at the Palmeiras fans. Three of the injured were also run over as drivers tried to flee the confrontation. Police were investigating whether Santos fans who were driving along the buses tried to hit the rivals on purpose.
Authorities had to partially block the busy highway that links the coastal city of Santos to Sao Paulo for nearly two hours.
Another Palmeiras fan died in August after a clash against Corinthians supporters before a league match. The 31-year-old man was hit on the head with iron bars and pieces of wood. The fight broke out after rival groups crossed paths at a train station outside Sao Paulo.
In February, a Santos fan was beaten to death by Sao Paulo supporters at a bus stop after a match between the teams.
This month, a fan of second-division club Avai died when a group of men threw rocks at the van he was in after a match. Police said at the time the attack likely came from a rival group.
There have been several other cases of violence inside and outside stadiums across Brazil this year, with fans using iron bars, homemade explosives and knives in confrontations. There were fights in at least three stadiums last month, and four Atletico Mineiro fans heading to a match sustained minor injuries after being shot at while at a bus stop.
Two different Corinthians fan groups clashed recently while fighting for spots at the team's new arena, and members of a Palmeiras group threw rocks and bottles at the team's bus after a loss earlier this year.
The fan violence has prompted Brazil's sports tribunal to punish a few clubs, including Corinthians and league leader Cruzeiro, making them play in front of empty stands or away from their stadiums.