The fighting prompted the Presidency of Yugoslavia to order the Yugoslav People's Army (Jugoslovenska Narodna Armija – JNA) to step in and create a buffer zone between the opposing forces.

The Yugoslav People's Army (Jugoslovenska Narodna Armija – JNA) confiscated Croatia's Territorial Defence (Teritorijalna obrana – TO) weapons to minimize resistance.

[1] On 17 August, the tensions escalated into an open revolt of the Croatian Serbs,[2] centred on the predominantly Serb-populated areas of the Dalmatian hinterland around Knin,[3] parts of the Lika, Kordun, Banovina regions and eastern Croatia.

[4] They established a Serbian National Council in July 1990, to coordinate opposition to Croatian President Franjo Tuđman's policy of pursuing independence for Croatia.

[6] In an effort to consolidate territory under their control,[7] Croatian Serb leaders organised a political rally at the Plitvice Lakes on 25 March 1991, demanding the area be annexed to the SAO Krajina.

Three days later, on 28 March, SAO Krajina special police seized the area,[8] and with the help of armed civilians, removed the Croatian management of the Plitvice Lakes National Park.

Journalist Tim Judah suggests that the move may have been motivated by a desire to control a strategic road that ran north–south through the park, linking the Serb communities in the Lika and Banovina regions.

[8] The Croatian police force, commanded by Josip Lucić, used several buses and passenger cars, as well as an armoured personnel carrier, to approach the Plitvice Lakes area.

[14] The approaching convoy was ambushed at a barricade set up by the SAO Krajina force near Plitvice Lakes before 7:00 in the morning of Easter Sunday, 31 March 1991.

The SAO Krajina force attacked the vehicles carrying the Croatian police and held their position until they fell back to the national park post office two and a half hours later.

Shortly afterwards, the Yugoslav Air Force dispatched a Mil Mi-8 helicopter to attend to wounded on both sides, and it left the area after an hour and a half.

The helicopter was dispatched by Colonel General Anton Tus, head of the Yugoslav Air Force at the time, following a request by Josip Boljkovac, Interior Minister of Croatia.

At the insistence of Serbia's representative on the Presidency, Borisav Jović, the JNA was ordered to intervene, gain control in the area and prevent further combat.

[17] The Serbian parliament also met in an emergency session, treating the clashes as a virtual casus belli and voting to offer the Krajina Serbs "all necessary help" in their conflict with Zagreb.

[18] Croatian authorities accused Serbia's president, Slobodan Milošević, of stage-managing the unrest in order to break Croatia's resolve to declare independence unless Yugoslavia was transformed into a loose confederation.

The march, led by Babić and Vojislav Šešelj, was prevented from reaching the Plitvice Lakes by the JNA and forced to return to Titova Korenica.