The unit that led this offensive was the Grmeč Shock Anti-Chetnik Battalion, formed earlier that month from wholly loyal and reliable troops. This offensive spelt the end of Drenović's "Petar Kočić" Chetnik Detachment, and Drenović took refuge with the Ustaše in Mrkonjić Grad.[23] On 27 April, he and other defeated Chetnik commanders signed an agreement with the NDH.