The siege of Mostar was fought during the Bosnian War first in 1992 and then again later in 1993 to 1994. Initially lasting between April 1992 and June 1992, it involved the Croatian Defence Council (HVO) and the Army of the Republic of Bosnia and Herzegovina (ARBiH) fighting against the Serb-dominated Yugoslav People's Army (JNA) after Bosnia and Herzegovina declared its independence from Yugoslavia. That phase ended in June 1992 after the success of Operation Jackal, launched by the Croatian Army (HV) and HVO. As a result of the first siege around 90,000 residents of Mostar fled and numerous religious buildings, cultural institutions, and bridges were damaged or destroyed.
As the wider conflict matured and the political landscape changed, the Bosnian Croats and Bosniaks began to fight against each other, culminating in the Croat–Bosniak War. Between June 1993 and April 1994 the HVO besieged Bosniak-concentrated East Mostar, resulting in the deaths of numerous civilians, a cut off of humanitarian aid, damage or destruction of ten mosques, and the blowing up of the historic Stari Most bridge. Hostilities ended with the signing of the Washington Agreement in March 1994 and the establishment of the Croat–Bosniak federation.
Background
In 1990 and 1991, Serb political leadership in Croatia and Bosnia and Herzegovina established a number of Serbian Autonomous Regions. As tensions escalated, elements of the Yugoslav People's Army (JNA) increasingly supported Serb forces in these areas. From late 1990, the JNA began arming Serb formations in Bosnia and Herzegovina and assisting in their organization. By March 1991, it had distributed an estimated 51,900 firearms to Serb paramilitary units and 23,298 firearms to members of the Serbian Democratic Party (SDS). The Croatian government began arming Croats in the Herzegovina region in 1991 and early 1992, anticipating the spread of the conflict into Bosnia and Herzegovina. It also provided support to elements of the Bosniak community. From July 1991 to January 1992, JNA units and Serb forces used Bosnian territory in operations against Croatia. During the war in Croatia, Bosnian president Alija Izetbegović issued a televised statement declaring neutrality, stating that "this is not our war", and the Sarajevo government initially did not take significant defensive measures against a potential attack by Bosnian Serb forces and the JNA.
On 25 March 1991, Croatian president Franjo Tuđman met with Serbian president Slobodan Milošević in Karađorđevo, reportedly to discuss the partition of Bosnia and Herzegovina. In November, the autonomous Croatian Community of Herzeg-Bosnia (HZ H-B) was established, it claimed it had no secessionary goal and that it would serve a "legal basis for local self-administration". It vowed to respect the Bosnian government under the condition that Bosnia and Herzegovina was independent of "the former and every kind of future Yugoslavia." Mate Boban was established as its president. In December, Tuđman, in a conversation with Bosnian Croat leaders, said that "from the perspective of sovereignty, Bosnia-Herzegovina has no prospects" and recommended that Croatian policy "support for the sovereignty [of Bosnia and Herzegovina] until such time as it no longer suits Croatia."
After the JNA's participation in the Croatian War of Independence, JNA units were regarded as an occupation force by the Croats of Mostar. It was perceived as a force friendly to the Serbs and hostile to Croats and Bosniaks (Bosnian Muslims). On 4 February 1992, local Croat citizens blockaded the roads from Mostar to Čitluk and Široki Brijeg in protest over the behavior of JNA reservists in the area. On 6 February Serbs blockaded the road from Mostar to Sarajevo. On 29 February and 1 March 1992 an independence referendum was held in Bosnia and Herzegovina. Independence was strongly favored by Bosniak and Bosnian Croat voters, while Bosnian Serbs largely boycotted the referendum. The majority of voters voted for independence and on 3 March 1992 president Alija Izetbegović declared independence from Yugoslavia, which was immediately recognised by Croatia.
On 14 March there was gunfire in Mostar with the JNA barracks in the city. On the following day the citizens of Mostar set up barricades and demanded the withdrawal of the JNA forces. On 1 April there were clashes between the JNA and Croat forces in several surrounding villages and the southern suburb of Jasenica. On 8 April, Bosnian Croats were organized into the Croatian Defence Council (HVO). A sizable number of Bosniaks also joined. On 15 April, the Army of the Republic of Bosnia and Herzegovina (ARBiH) was formed, with slightly over two-thirds of troops consisting of Bosniaks and almost one-third of Croats and Serbs. The government in Sarajevo struggled to get organized and form an effective military force against the Serbs. Izetbegović concentrated all his forces on retaining control of Sarajevo. In the rest of Bosnia and Herzegovina, the government had to rely on the HVO, who had already formed their defenses, to stop the Serb advance.
April 1992 – June 1992 siege
Prelude
In April fighting started at several locations in Herzegovina. The JNA's 2nd Military District, commanded by Colonel General Milutin Kukanjac, deployed elements of the 5th Banja Luka Corps and the 9th Knin Corps to the Kupres region, capturing the town from the Croatian Army (HV) and the HVO jointly defending the area in the Battle of Kupres on 7 April 1992, and threatening Livno and Tomislavgrad to the southwest. The 4th Military District of the JNA, commanded by General Pavle Strugar, employed the 13th Bileća Corps and the 2nd Titograd Corps to capture Stolac and most of the eastern bank of the Neretva River south of Mostar. The town of Široki Brijeg came under attack by the Yugoslav Air Force on 7 and 8 April.
Siege
JNA artillery attacks on Mostar suburbs started on 6 April and the city was from there on periodically shelled. Over the following week the JNA gradually established control over large portions of the city. On 9 April the JNA forces repelled an attack by the Croat forces, now as part of the HVO, on the Mostar military airfield. Bosnian Serb Territorial Defence Force captured two nearby hydroelectric power plants on the Neretva River on 11 April. On 19 April 1992, General Momčilo Perišić, the commander of the 13th Bileća Corps in Mostar, ordered the artillery units to attack the neighbourhoods of Cim, Ilići, Bijeli Brijeg and Donja Mahala. JNA forces in Mostar numbered at 17,000 soldiers.
In February 1992, in the first of many meetings, Boban, Josip Manolić, Tuđman's aide and previously the Croatian Prime Minister, and Radovan Karadžić, president of the self-proclaimed Republika Srpska, met in Graz, Austria to discuss the partition of Bosnia and Herzegovina and the necessary population transfers. On 6 May, Karadžić and Boban, without Bosniak representatives, met again in Graz and formed an agreement for a ceasefire and on the territorial division of Bosnia and Herzegovina. The agreement didn't include Mostar: the Bosnian Serbs maintained that eastern Mostar should be in the Serbian administrative unit, while the Bosnian Croats considered that all of Mostar should be in the Croatian one, based on the 1939 borders of the Banovina of Croatia. The parties ultimately parted ways and on the following day the JNA and Bosnian Serb forces, later renamed to Army of Republika Srpska (VRS), mounted an attack on Croat-held positions on the eastern river bank. Apart from a narrow band on the eastern bank of the Neretva, the Croats held Bijelo Polje to the northeast. The JNA held positions on the hills overlooking the city from the east, the Hum Hill south of the city, several suburbs to the south and a portion of area to the north.
The Croatian Army planned an offensive against the JNA and VRS codenamed Operation Jackal. The objective of the operation was to relieve Mostar and break the JNA encirclement of the besieged Dubrovnik. The preparations for the operation were done by HV general Janko Bobetko. Bobetko reorganized the HVO command structure. In late May the HVO forces began a series of attacks on the JNA and VRS positions around Mostar. On 23 May the HVO captured the Hum Mountain. Operation Jackal commenced on 7 June when HV/HVO force moved east and north from Čapljina towards Stolac and Mostar. In support of the main attack, the HVO attacked VRS positions on the west bank of the Neretva and on 11 June took the Orlovac Mountain and the villages of Varda, Čule and Kruševo to the southwest and Jasenica and Slipčići to the south. By the following day the HVO pushed all remaining VRS forces east of the Neretva River. On 13 June the Serb forces destroyed two bridges across the Neretva, leaving only the Stari Most bridge, which was, however, damaged.
Meanwhile, the HV/HVO force rapidly advanced and reached the suburbs of Mostar on 14 June. By 15 June HVO consolidated its hold of Stolac and the 4th Battalion of the Mostar HVO captured JNA "Sjeverni logor" barracks in Mostar. In order to complete a link up with the advancing HV and HVO units that were advancing to the north through Buna and Blagaj, the Mostar HVO forces, supported by the HV's 4th Battalion of the 4th Guards Brigade, moved south from the city through Jasenica. The two advancing forces met at the Mostar International Airport on 17 June. The HVO cleared the Bijelo Polje neighborhood in the northeast and advanced further east along the slopes of the Velež Mountain. After the withdrawal of VRS from eastern Mostar, the Serbs were expelled from the city. By 21 June the VRS was completely pushed out of Mostar. The ARBiH supported the eastward push from the city only in a secondary role. HVO was at the time composed of both Croats and Bosniaks. Although the frontline was still close to Mostar, the high ground directly overlooking Mostar on the eastern bank of the Neretva was secured by the HV and HVO forces. The HVO began establishing control of Mostar and upon takeover Boban dismissed Bosniaks from public life and in their place put HDZ hardliners, erected roadblocks around the city, and limited the freedom of movement of Bosniaks inside and outside Mostar.
Aftermath
Mostar was heavily damaged by JNA shelling during the siege. Amongst the destroyed or severely damaged buildings were the Catholic Cathedral of Mary, Mother of the Church, the Franciscan Church and Monastery, the Bishop's Palace (with a library collection of over 50,000 books), 12 out of 14 mosques, the historical museum, archives, and number of other cultural institutions. All of the city's bridges were destroyed, leaving only the Stari Most bridge as the remaining river crossing. In mid-June 1992, after the battle line moved eastward, the HVO demolished the Serbian Orthodox Žitomislić Monastery, while the Cathedral of the Holy Trinity was burned by an unidentified group. The JNA was accused of harassing non-Serbs and looting/burning the property of Bosniaks and Croats. About 90,000 of Mostar's 120,000 residents fled. Thousands of Bosniaks that left Mostar during the siege began to return into the city. They were followed by many Bosniak refugees from other Bosnian towns which had been overrun by the VRS.
In opinion polls conducted in Serbia during the 2000s by the Belgrade Center for Human Rights and Strategic Marketing Group less than 20 percent of respondents believed that the JNA actually besieged Mostar.
June 1993 – April 1994 siege
Prelude
Although originally on friendly terms, relations between the two allies had begun to deteriorate by the latter half of 1992. The Croatian government played a "double game" in Bosnia and Herzegovina and "a military solution required Bosnia as an ally, but a diplomatic solution required Bosnia as a victim". Tuđman's branch of the Croatian Democratic Union of Bosnia and Herzegovina (HDZ BiH) held important positions in the Bosnian government, including the premiership and the Ministry of Defence, but despite this it carried out a separate policy and refused to integrate the HVO into the ARBiH. Jerko Doko, the Bosnian defence minister, gave the HVO priority in the acquisition of military weapons. In January 1992, Tuđman had arranged for Stjepan Kljuić, president of the Croatian Democratic Union of Bosnia and Herzegovina (HDZ BiH) who favored cooperating with the Bosniaks towards a unified Bosnian state, to be ousted and replaced by Mate Boban, who favored Croatia to annex Croat-inhabited parts of Bosnia and Herzegovina. A rift existed in the party between Croats from ethnically mixed areas of central and northern Bosnia and those from Herzegovina. There were also regional lobbies with diverging interests within the Bosniak Party of Democratic Action (SDA), which included Sarajevo, Central Bosnia, Herzegovina, Bosanska Krajina and Sandžak.