A tense atmosphere prevailed on May 13, 1990, when a football game was held at Zagreb in Maksimir Stadium between Zagreb's Dinamo team and Belgrade's Red Star. The game erupted into violence between the Croatian and Serbian fans and with the police.
On 14 May 1990, the weapons of the TO of Croatia, in Croat-majority regions, were taken away by the JNA, preventing the possibility of Croatia having its own weapons as was done in Slovenia. Borisav Jović, Serbia's representative in the Federal Presidency and a close ally of Slobodan Milošević, claimed that this action came at the behest of Serbia.
After the election of Tuđman (Croatian President) and the HDZ, a Serb Assembly was established in Srb, north of Knin, on 25 July 1990 as the political representation of the Serb people in Croatia. The Serb Assembly declared "sovereignty and autonomy of the Serb people in Croatia".
On 21 December 1990, the SAO Krajina (Serbian Autonomous Oblast of Krajina) was proclaimed by the municipalities of the regions of Northern Dalmatia and Lika, in south-western Croatia. Article 1 of the Statute of the SAO Krajina defined the SAO Krajina as "a form of territorial autonomy within the Republic of Croatia" in which the Constitution of the Republic of Croatia, state laws, and the Statute of the SAO Krajina were applied.