Two people have been killed after violence broke out between sets of Boca Juniors supporters prior to a pre-season match in Buenos Aires.
Members of the Doce hooligan group became embroiled in a shootout just a few hours before the friendly with San Lorenzo was due to kick off.
Witnesses reported hearing gunshots near the Neuvo Gasometro stadium, with two men - believed to be 35 and 45 - confirmed dead after the shooting. The match was suspended following the violent clashes.
Sergio Berni, head of national security in Argentina, insists the scenes could have been avoided had away fans been prevented from travelling to the game.
"It was an impressive shootout, more than 100 shots," he told radio station La Red. "For 15 days we were insisting that the match is played without visiting support. Unfortunately what happened is what we feared.
"I hope that, from what has happened, we are aware that playing without visiting supporters is an option. We want weekends to be a party, and not a day of mourning."
Violence among supporter groups is endemic in Argentinian football. In June, a Lanus supporter was killed after a brawl with Estudiantes fans prompted police to use rubber bullets to disperse the crowd.