In September 1991, Bosnian Serbs had proclaimed a Serbian Autonomous Oblast with Bijeljina as its capital. In March 1992, the Bosnian referendum on independence was passed with overwhelming support from Bosniaks and Bosnian Croats, although Bosnian Serbs either boycotted it or were prevented from voting by Bosnian Serb authorities. A poorly organized, local Bosniak Patriotic League paramilitary group had been established in response to the Bosnian Serb proclamation.