This is a chanting that can be heard on every stadium, on every football match where the national team of Bulgaria plays.
Not so often it is used on rallies and protests. (especially anti-government ones, which are kinda traditional for Bulgaria).
The Bulgarian team is losing from Italy, the score is 1:2, but the fans are still supporting the team, just listen to them:
BULGARI IUNACI, BULGARI IUNACI, BULGARI IUNACI.
And now there is attach on the right, good raid, a pass, Milanov, GOOOOOOOOOAAALLLL!!!!