• Fans fight at Castelao and Porto Alegre World Cup arenas• ‘The infrastructure wasn’t made for Brazilian football fans,’ says police chief • ‘Holding back a rebellious mob is difficult,’ he adds • Pelé believes Brazil World Cup last year was a disaster for the hostsPolice fired percussion grenades inside the Castelao arena as fans fought at the 2014 World Cup stadium on Sunday following the end of the Ceara state championship final.