On 27 July the Ustaše lost control of Drvar . In the village of Trubar near Drvar , a Roman Catholic priest , Waldemar Maximilian Nestor , and his parishioners were killed by the insurgents . The NDH forces encircled Drvar , but lacked the artillery to capture the town . Eight battalions and several batteries were sent from Zagreb to the Drvar area , where an estimated 4,000 armed insurgents were located
killed
Trubar massacre
Srb uprising