MONTEVIDEO, Feb. 1 (Xinhua) -- Uruguay's Nacional expressed a deep "sense of shame" after their fans mocked rivals Chapecoense about the 2016 plane crash that devastated the Brazilian club.

A group of Nacional supporters made gestures referring to the tragedy during Nacional's 1-0 victory at Chapecoense's Conda Arena in a Copa Libertadores qualifier on Wednesday.

Nacional said they were investigating the incident and vowed that "those responsible would receive the most severe punishments".

"Unfortunately, many sick minds channel their irrationality to sporting scenarios", the Montevideo club said in a statement.

"Nacional made great efforts, as in general the clubs of the continent, to avoid such episodes.

"On behalf of the Nacional Football Club, we express to the president our deepest sympathy and deep sense of shame. We ask you to accept our deepest apologies."

South American football governing body CONMEBOL said it was also investigating.

Seventy-one people died - including 19 Chapecoense players and all of the club's coaching staff - when their LaMia chartered flight ran out of fuel and slammed into a mountain near Medellin in November 2016. There were six survivors.

The accident occurred just days before Chapecoense and Colombia's Atletico Nacional were due to play in the first leg of the Copa Sudamericana final in Medellin.

Chapecoense were later named winners of South America's second most important tournament at the request of Atletico Nacional.