Nacional apologise after fans taunt Chapecoense about plane crash
Nacional criticised the "sick minds" of fans who taunted rivals Chapecoense about the plane crash which killed 19 of the club's players and staff.
During the teams' Copa Libertadores match on Wednesday, some fans of Uruguayan club Nacional made gestures referring to the crash in 2016.
In a statement, Nacional apologised, adding the incident was "horrendous" and brought a "deep sense of shame".
The South American Football Confederation is now investigating.
Nacional said it would support the investigation and hoped "those responsible receive the most severe penalties".
"Unfortunately, many sick minds channel their irrationality to sporting scenarios", the statement read.
"National made great efforts, as in general the clubs of the continent, to avoid such episodes.
"On behalf of the National Football Club, we express to the president our deepest sympathy and deep sense of shame. We urge you to accept our deepest apologies."
Nacional claimed a 1-0 win in the first leg of the Copa Libertadores tie, with the return match in Uruguay on 7 February.
Chapecoense, from Brazil, had been due to play in the final of the Copa Sudamericana when their plane crashed on its approach to Medellin in November 2016, killing 71 people.
Opponents Atletico Nacional asked for Chapecoense to be awarded the cup, which was awarded to three surviving players when the team played their first game after the crash.
An investigation later found human error was the cause of the disaster.