The incident began when a group of 'U' fans tried to steal an Alianza Lima flag.
The classic matches between Universitario and Alianza Lima for the Federación Cup at VIDU (Campo Mar) ended with an incident in which shots were fired and the Peruvian National Police (PNP) had to intervene.
According to journalist Mario José Benites' Twitter account, alleged 'U' fans tried to snatch a flag that had been brought by the group of Alianza Lima to the training center of the Crema institution.
A scuffle broke out and then an individual - allegedly the father of one of the Alianza Lima players - fired three shots into the air, causing panic among the attendees at the 'U' headquarters.
Benites details that the shooter took refuge in the bus of the Victoriano club and later, PNP officers arrived at the scene and took the individual to the Lurín police station.