Violence had broken out in many places during and after the referendum . Armed Muslims known as " Green Berets " also erected barricades in and around Sarajevo . Barricades were erected near Banja Luka and a motorist was killed by armed Serbs in Doboj . Twelve people were overall killed before fighting died down on March 2 . On 3 March , Izetbegović claimed that Serbs from Pale were marching on Sarajevo . Meanwhile , clashes had begun at the same time in the town of Bosanski Brod , and eleven Serbs were killed in the village of Sijekovac outside of Brod on 26 March . The SDS stated they were massacred by a Croat-Muslim militia , which was denied . The town was besieged and shelled by the JNA and Serbian paramilitaries on 29 March in the lead-up to the war . In addition , there were also clashes in Bijeljina , which was attacked by a Serb force led by Serb Volunteer Guard . On 4 April , as the information of the killings in Bijeljina came to light , the Bosnian government announced a general mobilisation call . The SDS responded that armed conflict in Sarajevo had moved a step closer with the mobilisation call
killings
Bijeljina massacre
Siege of Sarajevo