The Zrinski Battalion was deployed for the first time on 15 June. It was stationed in Vukovar, tasked with preparation of city defences and organization and training of volunteer troops in Vukovar in June 1991. In August Filipović took over command of the battalion from Roso. The same month, the Zrinski Battalion went to Banovina, where it pushed the Croatian Serb forces out of the town of Hrvatska Kostajnica. In September, the battalion was deployed to Gospić, where it took part in battle to control Gospić against the JNA. Troops assigned to the battalion captured Kaniža barracks in Gospić. During combat in Gospić, 30 troops of the Zrinski Battalion, assisted by Lučko SPU, captured JNA Major General Trajče Krstevski, along with three armoured personnel carriers (APCs) and 32 soldiers. The unit was deployed to Metković on 28 October, tasked with recapturing Slano from the JNA. After the deployment to Gospić, a part of the unit personnel left to Bosnia and Herzegovina anticipating further conflict there, while the remainder of the unit returned to Kumrovec. The ZNG was renamed the Croatian Army ("Hrvatska vojska" – HV) on 3 November 1991. In late 1991, personnel of the Zrinski Battalion set up another special forces unit of the HV — the Matija Vlačić Battalion based in Opatija.