South America’s Copa Sudamericana was plunged into turmoil on Wednesday night when the last-16 return leg between Argentina’s Club Atlético Independiente and Universidad de Chile was abandoned because of violent clashes in the stands. The game, played at Independiente’s Estadio Libertadores de América in Avellaneda, was stopped in the 48th minute with the score 1-1 and the Chilean side leading the tie 2-1 on aggregate. The Buenos Aires provincial health ministry said at least 20 people were injured, 19 of them Chilean supporters. Two remain in neurosurgery and one is reported to be in critical condition. Among the most serious cases is 33-year-old Gonzalo Felipe Alfaro, who suffered head trauma and multiple fractures after falling from an upper tier while trying to escape attackers. Police detained more than 100 spectators; Chilean officials put the number of compatriots held at 101, while Argentine sources said the total could reach 125. Argentina’s Security Minister Patricia Bullrich said investigators are reviewing stadium footage and expressed surprise that initial arrests were almost exclusively of Chilean fans. Chilean President Gabriel Boric denounced the “inexcusable violence” and ordered Interior Minister Álvaro Elizalde to travel to Buenos Aires to assist injured nationals and monitor the legal process for those detained. The episode has drawn rebukes from regional football bodies, with CONMEBOL cancelling the fixture, citing a lack of security guarantees, and announcing that its disciplinary tribunal will determine sanctions against the clubs and, if applicable, local authorities.