One of the most popular sports in Mostar is football. The two most successful teams are HŠK Zrinjski and FK Velež. FK Velež won the Yugoslav Cup in 1981 and in 1986, which was one of the most significant accomplishments this club has achieved. Since the Bosnian War, each club has generally been supported by a particular ethnic group (Velež for the Bosniaks and Zrinjski for the Croats). The matches between the two clubs are some of the country's most intense matches. Since the start of the Premier League of Bosnia and Herzegovina, HŠK Zrinjski has won six championships.