Battle of Hrvatska Kostajnica

The Battle of Hrvatska Kostajnica was a military engagement fought between SAO Krajina and Croatian forces. Fought between Late July, 1991 to Early September of 1991. Croatian forces had successfully defended the town for months, briefly abandoning it. Since Croatian president Franjo Tuđman was inspecting troops in Hrvatska Kostajnica, SAO Krajina forces led by Branko Dmitrovic committed to occupying Hrvatska Kostajnica.

The Kninjas commanded by Dragan Vasiljković then showed up, and promptly ended the siege by breaking the outer defenses of Hrvatska Kostajnica, and making the Croatian Defenders surrender.

Background
In 1990, ethnic tensions between Serbs and Croats worsened after the electoral defeat of the government of the Socialist Republic of Croatia by the Croatian Democratic Union (Hrvatska demokratska zajednica – HDZ). The Yugoslav People's Army (Jugoslovenska Narodna Armija – JNA) confiscated Croatia's Territorial Defence (Teritorijalna obrana – TO) weapons to minimize resistance. On 17 August, the tensions escalated into an open revolt of the Croatian Serbs, centred on the predominantly Serb-populated areas of the Dalmatian hinterland around Knin (approximately 60 km north-east of Split), parts of the Lika, Kordun, Banovina and eastern Croatia. In January 1991, Serbia, supported by Montenegro and Serbia's provinces of Vojvodina and Kosovo, unsuccessfully tried to obtain the Yugoslav Presidency's approval for a JNA operation to disarm Croatian security forces. The request was denied and a bloodless skirmish between Serb insurgents and Croatian special police in March prompted the JNA itself to ask the Federal Presidency to give it wartime authority and declare a state of emergency. Even though the request was backed by Serbia and its allies, the JNA request was refused on 15 March. Serbian President Slobodan Milošević, preferring a campaign to expand Serbia rather than to preserve Yugoslavia with Croatia as a federal unit, publicly threatened to replace the JNA with a Serbian army and declared that he no longer recognized the authority of the federal Presidency. The threat caused the JNA to abandon plans to preserve Yugoslavia in favour of expansion of Serbia as the JNA came under Milošević's control. By the end of March, the conflict had escalated with the first fatalities. In early April, leaders of the Serb revolt in Croatia declared their intention to amalgamate the areas under their control with Serbia. These were viewed by the Government of Croatia as breakaway regions.

At the beginning of 1991, Croatia had no regular army. To bolster its defence, Croatia doubled its police numbers to about 20,000. The most effective part of the Croatian police force was 3,000-strong special police comprising twelve battalions organised along military lines. There were also 9,000–10,000 regionally organised reserve police in 16 battalions and 10 companies, but they lacked weapons. In response to the deteriorating situation, the Croatian government established the Croatian National Guard (Zbor narodne garde – ZNG) in May by expanding the special police battalions into four all-professional guards brigades. Under Ministry of Defence control and commanded by retired JNA General Martin Špegelj, the four guards brigades comprised approximately 8,000 troops. The reserve police, also expanded to 40,000, was attached to the ZNG and reorganised into 19 brigades and 14 independent battalions. The guards brigades were the only units of the ZNG that were fully equipped with small arms; throughout the ZNG there was a lack of heavier weapons and there was poor command and control structure above the brigade level. The shortage of heavy weapons was so severe that the ZNG resorted to using World War II weapons taken from museums and film studios. At the time, the Croatian weapon stockpile consisted of 30,000 small arms purchased abroad and 15,000 previously owned by the police. To replace the personnel lost to the guards brigades, a new 10,000-strong special police was established.

Battle
The Yugoslav People’s Army began their invasion of SAO Western Slavonia. Tanks and artillery were seen from across the Una. Intense artillery affected Hrvatska Kostajnica and the surrounding areas. Low-scale fighting occurred between July and Early August, which saw much Croatian success. Croatian forces withdrew from Hrvatska Kostajnica briefly, re-entering the town on August 2nd. The 7th Banija Division committed to occupying Hrvatska Kostajnica, with 1,000-2,000 troops. They outnumbered the Croatian garrison of only 400-450 defenders. The 7th Banija Division then cut off the road to Hrvatska Dubica, which is where the Croatian garrison stationed in Hrvatska Kostajnica got most of their supplies from. The road was captured by Serb forces, but was reportedly re-occupied by the Lučko Anti-Terrorist Unit and the 120th ZNG Brigade. The rest of the fighting devolved into an unsuccessful Croatian counter-attack to relieve the besieged town of Hrvatska Kostajnica. The Serbs besieging the town began to push for a final attack, to break the stalemate and occupy Hrvatska Kostajnica. This push came on August 30, Serbian forces captured the hill of Djed, that overlooked the town and was vital position. On the early morning of September 12th, Serbian forces captured 60 Croatian policemen, who were then brutally tortured, this was done to physiologically affect the Croatian defenders. The situation then completely collapsed as a failed Croatian offensive to break out of the siege and reach Hrvatska Dubica. The elite Knin police "Kninjas" (Serbian Cyrillic: (Knindže) arrived and broke-through the defenses of the town. They then forced the Croats into a section of the town near the Una (Sava). The Croatian defenders then surrendered and were sent to the Manjača camp where they were mistreated and executed.

Aftermath
The attacks on Hrvatska Kostajnica were a major success for the cause for Republic of Serbian Krajina, 60 Croatian Policemen captured, and many Capable and sufficient soldiers from the Zrinski Battalion and the 1st Guards Brigade (Croatia) were captured or killed.

Further advances
After Hrvatska Kostajnica was captured on September 13th, SAO Krajina forces captured Hrvatska Dubica the same day, Topusko on the 14th of September.

War crimes
After the strategic hill of Djed was captured, SAO Krajina forces captured 60 Croatian policemen, who were then tortured and executed. After the Kninjas pushed the remaining Croatian Soldiers into a section of the town that was near a bridge that led to the city of Kostajnica, Bosnia and Herzegovina, the Croatian garrison stationed at Hrvatska Kostajnica surrendered and were sent to the Manjača concentration camp where they would be tortured and killed. Following the capture of the town, Killings began as SAO Krajina forces torched and looted Hrvatska Kostajnica, and nearby villages.