After several months of increasing tension between the factions struggling for power within the insurgency, the first of the pro-Chetnik coups occurred, in the Ozren Partisan Detachment. It was sparked by the arrest and execution on 18 April of pro-Chetnik agitator Bogdan Jovićić by Vukmanović-Tempo and the newly formed 1st East Bosnian Shock Battalion. Fighting ensued between pro-Chetnik members of the detachment and the Shock Battalion. Vukmanović-Tempo then abandoned the Ozren Partisan Detachment, taking the detachment staff and remaining loyal Partisans with him.