During the fight, the suspect stabbed the victim with a knife. Despite efforts to resuscitate him, the victim died on the spot.
According to the police, the two men did not know each other beforehand.
Police are still looking for the suspect and another man who was with him at the time of the attack, both of whom have fled.
Sunday was supposed to be the last day of the fair, but city officials chose to end it early “out of respect for the victim,” Markus Lewe, Münster’s mayor, said in a statement.
The fair, also known as the Send, is held three times a year in Münster. According to the organizers’ website, it attracts up to a million visitors annually.