Red Army's biggest rivals today are Ultras Mostar, a supporter group of another team from Mostar HŠK Zrinjski Mostar. The rivalry is based both on locality, ethnicity and politics. FK Velež and Red Army are multietnic, while Zrinjski and Ultras are only Croats. Moreover, it is right to say that Red Army is left wing oriented while ultras are nationalistic right wing oriented. The rivalry began after the end of the Bosnian War, mostly because of conflict between Bosniaks and Croats during the war.