Operation Swath-10

Operation Swath-10 (Operacija Otkos-10) was a military offensive undertaken by the Croatian Army (Hrvatska vojska – HV) against the SAO Western Slavonia Territorial Defense Forces on the Bilogora Mountain, in the region of western Slavonia. The operation took place from 31 October to 4 November 1991 during the Croatian War of Independence and ended in a Croatian victory. The military success set the stage for follow-up advances by Croatian forces on the Papuk Mountain in Operation Papuk-91 fought in late November and December. By the end of the year, the HV gained control of the entire Papuk, securing transport routes between eastern Slavonia and the rest of Croatia.

The offensives were accompanied by the displacement of most of the Croatian Serb population of the area captured by the HV. The refugees initially fled to Bosnia and Herzegovina, but the majority were soon settled in the Yugoslav People's Army-held Baranja region in the east of Croatia. The event provoked accusations that the Croatian troops had committed ethnic cleansing and civil rights abuses in the offensive. The accusations were contradicted by a European Community Monitor Mission (ECMM) report made following an ECMM team tour of the area captured by the Croatian forces, two days after the offensive ended. During Operation Papuk-91, retreating White Eagles paramilitaries committed the Voćin massacre. The war crimes committed in Voćin were prosecuted at the International Criminal Tribunal for the former Yugoslavia.

Background
Within the 1991 Yugoslav campaign in Croatia, the 5th (Banja Luka) Corps of the Yugoslav People's Army (Jugoslovenska Narodna Armija – JNA) was tasked with advancing north through western Slavonia, from Okučani to Daruvar and Virovitica, and with a secondary drive from Okučani towards Kutina. This task was essentially consistent with the line expected to be reached by the main thrust of the JNA advancing from eastern Slavonia in about a week. The linkup was designed to facilitate a further advance west to Zagreb and Varaždin. The corps had already deployed a battlegroup of the 265th Mechanised Brigade near Okučani to support the advance that started on 21 September, and reached the Papuk Mountains. The corps received one artillery and two motorised brigades as reinforcements during the advance, but the problems with morale and desertions experienced by the JNA elsewhere were also present in the Banja Luka Corps.

The JNA was stopped by the Croatian National Guard (Zbor Narodne Garde – ZNG) between Novska, Nova Gradiška and Pakrac, even though SAO Western Slavonia Territorial Defense Forces (Teritorijalna odbrana – TO) units took positions on the Bilogora and Papuk north of Pakrac, near Virovitica and Slatina with no JNA support. The capture of Ivanovo Selo, east of Grubišno Polje and  north of Daruvar, on 21 September marked the territorial peak of the TO-held area on the Bilogora. The village was recaptured by the ZNG the same day at a cost of 7 dead and 15 wounded.

On 1 October, the Banja Luka Corps initiated probing attacks in the region, presaging a major effort employing the bulk of the corps three days later. The advance established defensive positions just outside Novska and Nova Gradiška. On 6 October, Pakrac was briefly isolated when the JNA captured Batinjani northwest of the town, interdicting the last road available for supply of Pakrac. The ZNG recaptured the village the same day and drove the JNA back, but it sustained 22 killed in the action. The JNA captured Jasenovac on 8 October. Lipik and a part of Pakrac were captured four days later. By that time the JNA offensive in western Slavonia had lost its momentum, and the ZNG made minor advances north of Novska and west of Nova Gradiška on 13 and 16 October. The Croatian authorities considered the war situation no longer critical. This assessment was followed by an order to prepare and implement plans for a counter-offensive on 15 October. On 29 October, the ZNG launched Operation Hurricane-91 against positions held by the JNA and the TO near Novska and Nova Gradiška.

Order of battle
The TO forces in the Bilogora Mountain region were formally a part of the 28th Partisan Division, commanded by Colonel Nikola Marić. In reality, the TO forces comprised approximately 1,750 soldiers provided with eight armoured vehicles, ten cannons and twelve mortars. The TO-force was organised in two battalions, headquartered in the villages of Mali Grđevac and Velika Peratovica, jointly commanded by Rade Čakmak. North of the TO-held area, the ZNG deployed the 127th Infantry Brigade in the Virovitica area. In the Grubišno Polje area, south of the Bilogora, the ZNG force was subordinated to the 57th Independent Battalion (later renamed the 77th Independent Battalion). The attacking ZNG force, under the command of Colonel Franjo Kovačević, consisted of 2,647 troops, supported by twelve armoured vehicles, eighteen cannons and twenty 120 mm mortars—surpassing the defending TO force in every aspect except for the close air support provided by the Yugoslav Air Force to the TO. The ZNG originally planned to deploy the 105th Infantry Brigade and "Omega" special police company from Bjelovar, but the two units had to be committed elsewhere and were not available for the offensive.

Timeline
Operation Swath-10 was formulated by the Croatians to regain control of the Virovitica–Lončarica–Grubišno Polje road, cutting off and destroying the TO forces deployed in the area of the road—the northernmost part of western Slavonia captured by the TO or the JNA. Those objectives were also designed to deny the Banja Luka Corps support if it attempted to break through towards Virovitica, controlling the last remaining supply route between Zagreb and Slavonia, shorten the Croatian defensive positions and improve the morale of the troops and civilian population. The offensive was originally scheduled for 15 October, but it was postponed for two weeks due to unavailability of the 105th Infantry Brigade and the special police. The operation plan expected the ZNG to cut off the two TO battalions on the Bilogora Mountain within two days of fighting, and the second stage of the offensive called for destruction of the trapped TO force. The operation was authorised by Colonel Miroslav Jezerčić, commander of Bjelovar Operational Zone, as early as 7 October.

The offensive was launched at 6 am on 31 October. A 50-minute artillery bombardment was followed by a ZNG advance in three groups. The 57th Independent Battalion advanced from the south, the 127th Infantry Brigade from the north and the 1st Battalion of the 127th Infantry Brigade from the northwest. The same day, the ZNG captured the villages of Velika Barna, Gornja Kovačica and Zrinska northwest of the Grubišno Polje–Veliki Grđevac road. That also secured the Grubišno Polje. The ZNG also advanced along the Virovitica–Grubišno Polje road, arriving at the outskirts of Mala Peratovica, east of Grubišno Polje, and approaching Lončarica,  south of Virovitica. The TO forces offered strong resistance, especially near Lončarica, even though the battlefield situation was described as hopeless. The TO requested close air support from the Yugoslav Air Force, and between four and six aircraft were deployed in response.

On 1 November, the ZNG conducted mopping-up operations in the areas northwest of Grubišno Polje. The next day, the TO force started to retreat towards the Papuk Mountain. Lončarica and Dapčevački Brđani (another village situated approximately northeast of Mala Peratovica along the Virovitica–Grubišno Polje road) were captured by the Croatian force on 3 November, after they defeated strong TO resistance. That day, the ZNG was renamed the Croatian Army (Hrvatska vojska – HV). After the two villages were captured, the HV forces advancing from Grubišno Polje and Virovitica linked up. The same day, the HV also captured the village of Velika Peratovica, isolated by the advances along the Virovitica–Grubišno Polje road and the advance northwest of Grubišno Polje made on the first day of the offensive. On 4 November, the operation was declared complete after the HV secured the entire area.

Battle of Bastajski Brđani
On 10 November, the 57th Independent Battalion advanced against the TO in the village of Veliki Miletinac, east of the area captured in Operation Swath-10, capturing the village the same day. Neighbouring Mali Miletinac was captured by the HV the next day. On 12 November, the HV captured the villages of Bastajski Brđani and Rekići. Two days later, the TO counterattacked, killing nine HV members and wounding approximately 10 more, but the HV defence held. Another effort to recapture Bastajski Brđani was made by the TO, reinforced with 50 White Eagles paramilitaries. The attack failed even though it was well prepared and supported by artillery because the defending HV force was alerted through signals intelligence and reinforced in anticipation of the attack. The White Eagles suffered 46 killed in the battle.

Operation Papuk-91
Operation Papuk-91 was devised as a follow-up of Operation Swath-10, involving advancing south from the Virovitica–Osijek road, aimed at clearing the Papuk and Psunj mountains of the TO forces, elements of the 28th Partisan Division. The offensive was approved by Jezerčić at a meeting in Slatina on 23 November. The meeting was attended by HV Inspector General Martin Špegelj, Colonel Miljenko Crnjac (commanding officer of the 123rd Infantry Brigade), Colonel Đuro Dečak (commanding officer of the 127th Infantry Brigade), Colonel Josip Černi (commanding officer of the 136th Infantry Brigade) and commanders of other units tasked with supporting the offensive.

The operation was launched on 28 November, and the HV advanced across a front spanning Grubišno Polje and Orahovica nearly 60 km further east. On 2 December, a detachment of the 123rd Infantry Brigade, en route to relieve troops manning a base on the Papuk, was ambushed and eleven soldiers were killed. On 10 December, the HV advanced onto the Psunj Mountain area north of Nova Gradiška in an effort codenamed Gradina, capturing the villages of Šnjegavić, Sinlije, Golobrdac, Vučjak Čečavski, Ruševac, Jeminovac, Čečavac and Opršinac. The advance improved the safety of the Nova Gradiška–Požega road and secured the right flank of the Nova Gradiška axis of Operation Hurricane-91.

Between 12 and 15 December, the HV captured a cluster of villages centred on Đulovac, southeast of the area captured in Operation Swath-10. The HV units approaching from the east captured Voćin, approximately southeast of Đulovac, on 14–15 December. Both Voćin and Đulovac were badly damaged by the retreating TO and the White Eagles paramilitaries. In addition, the retreating White Eagles killed 43 civilians in Voćin on 13 December. Bodies of the victims were mutilated and left unburied, presumably as a warning to others.

On 16 December, the HV captured the villages of Gornji Vrhovci, Kamenski Vučjak and Kamenski Šušnjari situated approximately 15 km south of Voćin and 10 km west of Velika, restricting the TO forces to the southwest edge of the Papuk Mountain and the Psunj Mountain further south in operation codenamed Sokolina. The following day, the HV captured Novo Zvečevo and a TO supply depot in the village, located halfway between Voćin and Kamenski Vučjak. The attack on Novo Zvečevo was codenamed Johanesberg. On 18 December, the HV advanced southwest from Kamenski Vučjak (advance codenamed Laništa), capturing the villages of Striježevica, Bogdašić, Amatovci and Kamenski Šeovci, arriving within of the village of Kamenska situated on the Pakrac–Požega road. During the following three days the HV performed mopping up operations in the area.

On 21 December, the HV launched a failed attack on Kamenska and the adjacent village of Mijači (codenamed Prkos). The TO withdrew from the area north of Kamenska, including the village of Sažije on 24 December, and it retreated from Kamenska and Mijači the next day. The HV forces deployed in the area of Pakrac, west of the Papuk and the Psunj, advanced east to support Operation Papuk-91, capturing the villages of Dereza, Gornji Grahovljani, Donji Grahovljani, Kusonje and Španovica on 24–25 December, leaving less than 15 km of the Pakrac–Požega road in between the HV units advancing from the west and the east. Operation Papuk-91 was concluded on 26 December, when the forces of the 123rd, the 127th and the 136th Brigades linked up at Bučje. The advance of the final day was codenamed Velebit.

Aftermath
In Operation Swath-10, the HV sustained the loss of five dead. It captured 370 km2 of western Slavonia containing 21 villages. While the HV met the objective of securing the Virovitica–Grubišno Polje road it failed to trap the TO troops deployed to the area. This was later attributed to insufficient forces required to accomplish the goal, specifically unavailability of the 105th Infantry Brigade or possibly the 73rd Independent (Garešnica) Battalion. The two units were deployed in the area of Pakrac instead. The positions reached by the HV set the stage for further advance against the SAO Western Slavonia in Operation Papuk-91. Some sources conflate Operations Swath-10 and Papuk-91, presenting the latter as a part of Operation Swath-10. Operation Papuk-91 completely eliminated threat to the road connecting the eastern Slavonia and Zagreb because the TO forces were pushed sufficiently far south, placing the road out of range of artillery. In Operation Papuk-91, the HV captured 110 settlements, as well as approximately 1230 km2 of territory.

In 2008, a monument to the HV troops who took part in the offensive was unveiled in Grubišno Polje. Another monument was erected on the Papuk Mountain to the 11 soldiers of the 123rd Infantry Brigade ambushed in Operation Papuk-91 on 2 December 1991. Operations Swath-10, Papuk-91, and Hurricane-91, executed in western Slavonia in late 1991, are considered to be the first Croatian offensive operations of liberation in the Croatian War of Independence.

The International Criminal Tribunal for the former Yugoslavia (ICTY) charged Vojislav Šešelj with a series of war crimes, including the killings committed by the White Eagles paramilitaries in Voćin on 13 December. The trial concluded in 2012, but the verdict is still pending. Slobodan Milošević, President of Serbia at the time of the killings, was also charged by the ICTY for the crimes committed in Voćin. Milošević died before his trial at the ICTY was completed.

Refugees
The Croatian Serb civilian population fled the area affected by Operation Swath-10. According to Serbian sources, the population started to flee on the first day of the offensive, and by the second day approximately 800 vehicles left the region and crossed into Bosnia and Herzegovina. The retreating columns included men of military age who refused to fight. A substantial proportion of the refugees were settled in Baranja, in houses owned by Croats displaced from the region. Based on the reports of the fleeing civilians, the Yugoslav government accused Croatia of ethnic cleansing and other civil rights violations. Deputy prime minister Aleksandar Mitrović wrote to the European Community Monitor Mission (ECMM), accusing Croatia of causing numerous casualties, devastation and displacement of Serb civilians. Even though the accusations were contrasted by evacuation plans put together by SAO Western Slavonia authorities on 25 October, and by testimony of civilians who remained in the area and claimed that the TO called the population to flee claiming "Ustaše are coming [...] killing every Serb", media in Serbia widely reported on alleged atrocities. The reports related the Croatian offensive to World War II and massacres committed by the Independent State of Croatia in that period. On 3 November, the Presidency of Yugoslavia condemned the offensive citing the destruction of 18 Serb villages, and the next day the National Assembly of Serbia appealed to the international community for help.

In response to the situation and a request received from the Presidency of Yugoslavia, an ECMM team toured the area affected by the offensive on 6 November, targeting those locations where the media reports indicated the atrocities occurred, including Velika Peratovica, Mala Peratovica, Gornja Rašenica, Donja Rašenica and Lončarica. The ECMM report of 6 November refuted the accusations. The ECMM team found only one Serb couple remaining in the area, but they denied claims that the HV mistreated the civilians left behind. The ECMM team reported that there was no systematic destruction of houses, even though a number of structures exhibited artillery bombardment damage and a small number of houses, farms and haystacks had been recently torched. However, the report states that the team was unable to determine if the HV was to blame, or if the villagers took revenge against SAO Western Krajina leaders, or if the destruction was a result of a scorched earth policy applied by the retreating force.

The HV offensives in western Slavonia conducted in late 1991—Operations Hurricane-10, Swath-10, and Papuk-91—created a total of 20,000 Serb refugees. They fled from the area when the JNA ordered the Croatian Serb forces to withdraw, and were subsequently settled in JNA-held Baranja region in the east of Croatia.

Ceasefire
A ceasefire of 3 January 1992 allowed for the implementation of the Vance plan, which provided for the protection of civilians in specific areas designated as UN Protected Areas (UNPAs) and deployment of UN peacekeepers in Croatia. One of the UNPAs defined by the plan, UNPA Western Slavonia, encompassed parts of the municipalities of Novska and Nova Gradiška, as well as the entire municipalities of Daruvar, Grubišno Polje and Pakrac. Thus the UNPA covered the area held by the JNA on 3 January, additional territory to the north, recaptured by the HV in late 1991, and towns which never came under SAO Western Slavonia control—such as Grubišno Polje and Daruvar. The peacekeeping force named United Nations Protection Force (UNPROFOR), initially expected to be 10,000-strong, started to deploy on 8 March.