Battle of Osijek

The Battle of Osijek (Bitka za 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 airstrikes 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 crimes 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 shelters.

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 crimes 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.