Operation Jackal Operation Jackal ( ) , also known as Operation June Dawns ( Croatian : " Operacija Lipanjske Zore " ) , was an offensive of the Bosnian War fought between a combined Croatian Army ( HV ) and Croatian Defence Council ( HVO ) army against the Army of Republika Srpska ( VRS ) from 7 – 26 June 1992 . The offensive was a Croatian pre - emptive strike against the VRS , a Bosnian Serb military formed in May 1992 from JNA units that were stationed in Bosnia and Herzegovina . The HV concluded that the Yugoslav People ' s Army ( JNA ) offensive operations of April and May 1992 , resulting in the capture of Kupres and much of the Neretva River valley south of Mostar , were aimed at capturing or threatening the Croatian Port of Ploče and possibly Split . To counter this threat , the Croatian leadership deployed the HV , under the command of General Janko Bobetko , to the " Southern Front " including the area in which Operation Jackal was to be conducted . The offensive marked the first significant Bosnian Serb defeat in the war and placed the HV in a favourable position to push back the VRS and remnants of the JNA holding positions north and east of Dubrovnik . The HV later re - established overland links with the city which had been under siege by the JNA since late 1991 . The attack resulted in an HV / HVO victory and the capture of approximately of territory in and around Mostar and Stolac . Background . In August 1990 , a Serbian uprising occurred in Croatia centred on the Dalmatian hinterland around the city of Knin , parts of the Lika , Kordun , and Banovina regions , as well as in settlements in eastern Croatia with significant Serb populations . The areas were subsequently named the Republic of Serbian Krajina ( RSK ) . The RSK , supported by Serbia , declared its intention to integrate with Serbia , and was denounced by the Government of Croatia as a rebellion . Tensions rose and by March 1991 the Croatian War of Independence had broken out . With the disintegration of Yugoslavia , in June 1991 Croatia issued its declaration of independence which became official on 8 October after a three - month moratorium . The RSK then initiated a campaign of ethnic cleansing against Croatian civilians and most non - Serbs were expelled by early 1993 . In May 1991 , the Croatian National Guard ( ZNG ) , subsequently renamed the Croatian Army ( HV ) in November , was formed as a result of growing support for the RSK from the Yugoslav People ' s Army ( JNA ) and the inability of the Croatian Police to cope with the situation . The establishment of the military of Croatia was hampered by a UN arms embargo introduced in September . The final months of 1991 saw the fiercest fighting of the war culminating in the Battle of the Barracks , the Siege of Dubrovnik , and the Battle of Vukovar . In January 1992 , the Sarajevo Agreement was signed by representatives of Croatia , the JNA and the UN , and a ceasefire called . After a series of unsuccessful ceasefires , the United Nations Protection Force ( UNPROFOR ) was deployed to Croatia to supervise and maintain the agreement . The conflict largely passed on to entrenched positions , and the JNA soon retreated from Croatia into Bosnia and Herzegovina , where a new conflict was anticipated . As the JNA withdrew from Croatia , it was reorganised into a new Bosnian Serb army and later renamed the Army of Republika Srpska ( VRS ) . This reorganisation followed the declaration of the Serbian Republic of Bosnia and Herzegovina on 9 January 1992 , ahead of the 29 February – 1 March 1992 referendum on independence of Bosnia and Herzegovina . This declaration would later be cited as a pretext for the Bosnian War . Bosnian Serbs began fortifying the capital , Sarajevo , and other areas on 1 March . On the following day , the first fatalities of the war were recorded in Sarajevo and Doboj . In the final days of March , the Bosnian Serb army bombarded Bosanski Brod with artillery , drawing a border crossing by the HV 108th Brigade in response . On 4 April , Serb artillery began shelling Sarajevo . The JNA and the VRS in Bosnia and Herzegovina faced the Army of the Republic of Bosnia and Herzegovina ( ARBiH ) and the Croatian Defence Council ( HVO ) , reporting to the Bosniak - dominated central government and the Bosnian Croat leadership respectively , as well as the HV , which occasionally supported HVO operations . Prelude . In April 1992 , the JNA renewed offensive operations against the HV and the HVO in areas of western and southern Herzegovina near Kupres and Stolac . 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 HV and the HVO jointly defending the area in the 1992 Battle of Kupres on 7 April 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 fighting around Mostar and JNA artillery attacks on the city started on 6 April , with the town of Široki Brijeg coming under attack by the Yugoslav Air Force on 7 – 8 April . While a Croatian attack of 9 April failed to capture a JNA - controlled airfield in Mostar , the Bosnian Serb Territorial Defence Force captured two nearby hydroelectric power plant s on the Neretva River and the JNA pushed the HV / HVO force from Stolac on 11 April . Čapljina , southwest from Mostar , came under intermittent JNA artillery and air attacks . A ceasefire was arranged on 7 May , but the JNA and the Bosnian Serb forces resumed the attack the next day . The attack succeeded in capturing a large part of Mostar and some territory on the west bank of the Neretva River . On 12 May , the JNA forces based in Bosnia and Herzegovina became a part of the VRS . While the JNA planned the offensive to pre - empt a Croatian attack on Serb - held territory , Croatia saw the moves as a prelude to JNA attacks on southern Croatia , specifically aimed at the Port of Ploče and possibly Split . To counter the perceived threat , the HV deployed additional troops to the area redesignated as the " Southern Front " . HV General Janko Bobetko , appointed to command the Southern Front , reorganised the HVO command structure and assumed command of the HVO in the area to stop the expected JNA / VRS offensive and regain the lost territory along the Neretva River . In late May , Bobetko launched an attack along the Adriatic coast , and in its immediate hinterland , towards besieged Dubrovnik linking up with the HV force in the city and breaking the JNA encirclement of the city by 1 June . The attack coincided with a JNA withdrawal towards Dubrovnik Airport in Konavle and positions within Bosnia and Herzegovina borders , away from the coast . On 23 May , the HV / HVO captured the Hum Mountain south of Mostar . Order of battle . The HV and the HVO committed 4 , 670 troops to Operation Jackal . The HVO deployed various units stationed or raised in the area , mostly drawn from Mostar , Široki Brijeg , and Čitluk . The HV contributed the 4th Guards Brigade , elements of the 116th Infantry Brigade and the 156th Infantry Brigade . The HV troops were deployed around Čapljina , for the main attack across the Neretva River and on the right flank of the axis , while the HVO troops were deployed to their left , as well as in the Čapljina area . The VRS Herzegovina Corps ( former JNA 13th Bileća Corps ) , commanded by Major General Radovan Grubač , consisted of the 10th and 13th Brigades as well as Ljubinje Territorial Defence troops in the area of Mostar and Stolac . Timeline . Operation Jackal , or alternatively Operation June Dawns , commenced on 7 June 1992 . The attacking HV / HVO force moved east and north from Čapljina towards Stolac and Mostar aiming to push the VRS back from the Neretva River and capture positions around Mostar . The HV / HVO force captured the first objective of the offensive , the town of Tasovčići located across the Neretva River , opposite Čapljina , on 8 June . The HV component of the force which captured Tasovčići , the 156th Infantry Brigade , was detached from the force tasked with continued advance to capture Klepci and Prebilovci to protect the right flank of the Neretva bridgehead . The HV 116th Infantry Brigade held the Neretva River valley south of the bridgehead and east of Metković . As the VRS Herzegovina Corps positions around Tasovčići collapsed , the attacking forces were able to quickly move east along its planned line of advance . On 11 June , the Mostar HVO forces attacked VRS positions on the west bank of the Neretva River , south of the city of Mostar in support of the main attack . The advance was immediately successful , capturing the villages of Varda , Kruševo , Jasenica , Slipčići and the Orlovac Mountain . The HVO captured JNA / VRS Heliport Barracks in Mostar the same day . On 12 June , the HVO pushed all remaining VRS forces east across the river . The 1st Herzegovina Brigade of the HVO and the 156th Infantry Brigade advanced northeast from Čapljina and captured villages of Bivolje Brdo and Lokve away from the Neretva crossing point . The 116th Infantry Brigade , spearheading the Tactical Group - 2 , consisting of the brigade and supporting HVO troops , staged a rapid breakthrough and reached outskirts of Stolac , approximately east of the Neretva crossing . The advance northeast towards Mostar continued north through Pijesci and Gubavica and reached the southern approaches to Mostar on 14 June . HVO units attacking from Čapljina secured Stolac by capturing VRS positions in Hodovo , approximately north of Stolac , on 15 June . The same day , the 4th Battalion of the Mostar HVO captured JNA " Sjeverni logor " barracks in Mostar while other elements of the HVO Mostar force captured nearby Fortica Hill overlooking the city . The final part of the northward advance of the force that set off from Čapljina was routed through Buna and Blagaj villages , which were also captured on 15 June . In order to complete a link up with the advancing HV and HVO units , 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 HV and the HVO completely pushed the VRS from Mostar , advancing further east along the slopes of the Velež Mountain and capturing high ground overlooking the city by 21 June . The ARBiH supported the eastward push from the city only in a secondary role . Even though the front lines did not move significantly to the east , the city of Mostar was relatively secure from future VRS attacks . The offensive is considered to have ended on 26 June , when the HVO captured the Merdžan Glava peak of the Velež Mountain . Aftermath . The HV and the HVO captured approximately of territory during Operation Jackal , and the supporting attacks around Mostar , as well as handing the VRS their first significant defeat in the Bosnian War . The offensive removed a direct threat posed by the JNA and the VRS to Metković , and it accomplished the Croatian objective of capturing positions that were favourable to staging further offensives against JNA and VRS forces still positioned near Dubrovnik . The follow - up Operation Tiger was the first HV offensive to exploit the success of Operation Jackal and improve Croatian military positions on the Southern Front in general but specifically around Dubrovnik . HV deployment to Bosnia and Herzegovina not only gained them significant experience in the execution of large - scale military offensives , but also denied the Bosnian Serb VRS forces the chance to pursue a decisive victory .