Liverpool striker Darwin Nunez led Uruguay players into the crowd after their Copa America defeat to Colombia. Nunez was seen swinging punches at Colombian fans and exchanging blows.
Nunez is now facing an international ban, but UFF president Ignacio Alonso says: "The Uruguayan players had an instinctive and natural reaction to defend and protect the children, women, parents and relatives who were in the stands and were being attacked.
"It was an instinctive reaction."
The South American Football Confederation (CONMEBOL) have since announced: "In light of the acts of violence that occurred at the end of the match between the national teams of Uruguay and Colombia, the disciplinary commission has decided to open an investigation to clarify the sequence of facts and the responsibilities of the people involved.
"It is unacceptable that an incident like this turns passion into violence. Therefore, any behavior that violates the spirit of sport and the most beautiful show in the world, which belongs to all families, will not be tolerated."