Buenos Aires: Boca Juniors fans fired pepper spray at rival River Plate players forcing authorities to halt a Copa Libertadores game in the latest violence to hit world football.

Four River Plate players suffered burns, according to media reports. Players were returning for the second half of the game, deadlocked at 0-0, when the shocking attack was staged by fans among the 60,000 capacity crowd in Boca’s Bombonera Stadium.