The World Cup qualifier between Brazil and Argentina was delayed by half an hour after police clashed with fans at a sold-out Maracanã Stadium. Brazilian police charged Argentina fans in response to fighting in the stands during the national anthems. Visiting supporters responded by ripping up and throwing seats at the officers. Fans near the trouble panicked and came on to the pitch to escape the fighting. At least one injured fan was taken out on a stretcher.
source: theguardian.com