Battle of Osijek The Battle of Osijek ( ) was the artillery bombardment of the Croatian city of Osijek by the Yugoslav People ' s Army ( JNA ) from August 1991 to June 1992 , during the Croatian War of Independence . The shelling peaked in late November and December 1991 and diminished in 1992 , after implementation of the Vance plan was agreed upon by the belligerents . The bombardment was compounded by limited JNA armour and infantry attacks aimed at enveloping the city . The Yugoslav Air Force executed several airstrike s against targets in the city . The bombardment killed approximately 800 in Osijek , while a large portion of the city ' s population fled . It is estimated by Croatian sources that 6 , 000 artillery shells were fired against Osijek in the period . After the JNA captured Vukovar on 18 November , Osijek appeared to be the next target of its campaign in Croatia . The JNA units subordinated to the 12th ( Novi Sad ) Corps , supported by the Serb Volunteer Guard achieved modest advances in late November and early December 1991 , capturing several villages south of Osijek , but the defensive line in the region was successfully maintained by the Croatian Army and the advances contained . Croatian authorities charged thirteen JNA officers with war crime s against civilian population of Osijek , but none of them have been arrested . Background . In 1990 , following the electoral defeat of the government of the Socialist Republic of Croatia , ethnic tensions worsened . The Yugoslav People ' s Army ( " Jugoslovenska Narodna Armija " – JNA ) confiscated the weapons of Croatia ' s Territorial Defence ( " Teritorijalna obrana " – TO ) to minimize potential resistance . On 17 August , the tensions escalated into an open revolt by Croatian Serbs , centred on the predominantly Serb - populated areas of the Dalmatian hinterland around Knin , parts of the Lika , Kordun , Banovina regions and eastern Croatia . In January 1991 , Serbia , supported by Montenegro and Serbia ' s provinces of Vojvodina and Kosovo , made two unsuccessful attempts to obtain approval from the Yugoslav Presidency to deploy the JNA to disarm Croatian security forces . After a bloodless skirmish between Serb insurgents and Croatian special police in March , the JNA itself , supported by Serbia and its allies , asked the federal Presidency to grant it wartime powers and declare a state of emergency . The request was denied on 15 March , and the JNA came under the control of the Serbian President Slobodan Milošević by the summer of 1991 , as the Yugoslav federation started to fall apart . By the end of the month , the conflict had escalated , and the first fatalities occurred . The JNA then stepped in to support the insurgents and prevent Croatian police from intervening . In early April , leaders of the Serb revolt in Croatia declared their intention to integrate the area under their control with Serbia . The Government of Croatia considered this an act of secession . Bombardment . The JNA intervened directly against Croatia for the first time on 3 July 1991 , driving Croatian forces out of Baranja , north of the city of Osijek , and out of Erdut , Aljmaš and Dalj east of Osijek . The advance was followed by intermittent fighting around Osijek , Vukovar and Vinkovci . At several points , the JNA positions were within several hundred yards from Osijek . The JNA units near Osijek were subordinated to the 12th ( Novi Sad ) Corps , commanded by Major General Andrija Biorčević . In the city itself , the JNA had several barracks where the 12th Proletarian Mechanised Brigade and the 12th Mixed Artillery Regiment were stationed . The 12th Proletarian Mechanised Brigade contained one of a handful battalions JNA maintained at full combat readiness . The city was defined as their starting point in a planned westward offensive towards Našice and Bjelovar . Croatian forces in the area were formally subordinated to Operational Zone Command in Osijek , headed by Colonel Karl Gorinšek . Regardless , defence of Osijek was commanded in practice by Branimir Glavaš , then head of the National Defence Office in Osijek , according to information presented at Glavaš trial in the 2000s . Glavaš formally became commander of the city defences on 7 December 1991 . The JNA first attacked Osijek by mortar fire on 31 July 1991 , and its centre was heavily bombarded on 19 August . The attacks came from positions north , east and south of Osijek , and were supported by JNA garrisons stationed in Osijek itself . On 7 – 9 September , an inconclusive battle was fought in Tenja , within of the city . The JNA garrisons were besieged by Croatian forces in mid - September . After a barracks in the city centre were captured on 15 September , the remaining JNA garrison broke out from the besieged barracks after heavy fighting with Croatian troops and reached JNA positions south of Osijek on 17 September . Intensity of the shelling increased and peaked in November and December . After a ceasefire was arranged in January 1992 , following acceptance of the Vance plan , the artillery attacks became intermittent , and ceased by June . After JNA captured Vukovar on 18 November , the JNA 12th ( Novi Sad ) Corps , supported by the Serbian Ministry of Interior - trained Serb Volunteer Guard paramilitaries , started to advance west between Vinkovci and Osijek 20 November . The city of Osijek appeared to be the next target of the JNA , which was later confirmed by General Života Panić , commander of the JNA 1st Military District . On 21 November , the JNA captured villages of Stari Seleš , Novi Seleš and Ernestinovo situated approximately to the south of Osijek . Laslovo , south of Ernestinovo was captured three days later . Those developments threatened Đakovo and encirclement of Osijek . On 4 December 1991 , the Special Envoy of the Secretary - General of the United Nations Cyrus Vance visited Osijek to inspect the damage . In early December , the JNA made modest advances , capturing Antunovac located south of Osijek on 5 December 1991 . On the same day , an armoured JNA force unsuccessfully attacked positions held by Croatian 106th Brigade in Rosinjača Forest near Nemetin , approximately east of Osijek . On 6 December , the JNA pushed Croatian troops out from Tenja . The JNA captured Paulin Dvor , less than kilometers west from Ernestinovo , on 16 December . The Croatian Army managed to contain the JNA attacks , even though the fighting continued south of Osijek until January 1992 . During its height , the intensity of the bombardment was reported to reach one shell per minute at times , and the artillery attacks were compounded by Yugoslav Air Force strikes against the city . According to Croatian sources , a total of 6 , 000 artillery shells were fired against Osijek in the period . Civilian population of Osijek , amounting to 104 , 761 residents of the city and 129 , 792 in the municipality of Osijek in 1991 , was significantly reduced as the people took refuge . It is estimated that a third of the population remained in the city by the end of November , while some sources estimate that the population of the city was reduced to just 10 , 000 people during the most intense periods of the bombardment . Those remaining in Osijek normally slept in bomb shelter s . Aftermath . By June 1992 , approximately 800 people had been killed by the bombardment . By the end of the Croatian War of Independence in 1995 , a total of 1 , 724 people from Osijek had been killed , including 1 , 327 soldiers and 397 civilians . The city itself suffered great damage during the war , with the bulk of direct damage occurring as a consequence of the 1991 – 92 bombardment . The total direct war damage sustained by the city is estimated at US $ 1 . 3 billion . The damage was regularly recorded by 400 volunteers during the bombardment . Even though media reported on the bombardment of Osijek , journalists in the city itself felt that it was receiving unduly low level of media coverage compared to wartime events elsewhere in Croatia . The attacks on Osijek were welcomed by the " Pravoslavlje " newspaper published by the Serbian Orthodox Church , which appeared to give a blessing to the attack as a part of a " holy war " , setting it in the context of World War II massacres and concentration camps in the Independent State of Croatia . In 2008 , Croatian authorities formally charged Colonel Boro Ivanović , commanding officer of the JNA 12th Proletarian Mechanised Brigade , and twelve other JNA officers with war crime s against the civilian population . The charges include causing death of 307 civilians in Osijek and its surroundings , severe injuries to a further 171 people and the destruction of at least 1 , 188 different structures . , all of the indicted officers remain at large in Serbia . Glavaš and five other persons have been charged and convicted of eleven counts of murder , one attempted murder and of the torture of Serb civilians found in the JNA barracks , which surrendered on 15 September . Glavaš was handed a sentence of ten years in prison and the remainder received prison sentences of between five to eight years . To avoid extradition , before the conviction became final Glavaš fled to Bosnia and Herzegovina , having been granted citizenship . His sentence was reduced to eight years and became final in 2010 , when he was arrested and imprisoned in Bosnia and Herzegovina . Even though the JNA withdrew from Croatia in 1992 , it contributed personnel and equipment to the Army of the Republic of Serbian Krajina ( ARSK ) in the areas previously held by the JNA . Even though the United Nations Protection Force peacekeepers deployed to the area on the basis of the Vance plan and placed most of the ARSK heavy weapons in storage , Osijek was intermittently bombarded throughout the war — the last artillery strike happened in September 1995 . The hostilities ceased in November 1995 through the Erdut Agreement securing restoration of Croatian rule in the region .