a game between the two clubs in the last game of the season OFK scored a last minute equalizer against Rad meaning Rad were relegated for the first time in almost twenty-five years. In the following season when OFK were playing in the Intertoto Cup Rad fans threw a number of flares from outside the stadium forcing UEFA to award the game 3–0 against OFK even though OFK won the game 6–1 against Estonian club Narva Trans. Other rivals to a much lesser degree include FK Crvena zvezda and FK Partizan. After being relegated to Serbian League Belgrade OFK have a bitter rivalry with FK Zemun. Supporters OFK Beograd's fans are commonly known as Plava Unija (The Blue Union) since 1994. When Beogradski Sportski Klub (BSK) was founded in 1911, the club which dominated the fields of the Kingdom of Serbs, Croats and Slovenes developed a significant fan base. Throughout the several wars that took place since the founding of BSK, the club's turbulent history has produced adverse effects on the average attendance of today's matches in which OFK Beograd plays. An organized group appeared for the first time in 1984 under the name of "Blue Thunders". The group lived under that name until 1990. When they were influenced by the rise of nationalism in Yugoslavia, they change their name to "Sokolovi" (The Falcons). The group officially collapsed in 1993 about a year after UN sanctions were put on FR Yugoslavia. The fans' love towards the club was certainly not forgotten and in 1994 a new group is founded – Blue Union Belgrade. The name remains the title of OFK Beograd's main group of ultras. OFK Beograd's fans have been known to be resistant of past regimes. In the 1990s, Milicionar, a pro-regime police-backed team, entered the first division. When OFK Beograd first played against them, the OFK fans reacted with creation of a banner which bore the message "Goal Against the Regime." Among other things, members of Plava Unija also reinstated the old ex-Yugoslav firms habit of finding local home crews when their team was on away matches, no matter which Serbian town or city was in question. Plava Unija fostered a friendship with Voždovac's fans, "Invalidi" while the club still played in Yugoslavia's second tier from 1996 to 1998. That friendship still remains to this day. OFK Beograd is also known to be supported by fans of Dynamo