 While the Chetniks were an anti @-@ Axis movement in their long @-@ range goals and did engage in marginal resistance activities for limited periods , they also carried out almost throughout the war a tactical or selective collaboration with the occupation authorities against the Partisans . The Chetnik movement adopted a policy of collaboration with the Axis powers , and engaged in cooperation to one degree or another by establishing modus vivendi or operating as auxiliary forces under Axis control . This was demonstrated in late 1942 and early 1943 , when Ostojić planned and oversaw the Chetnik involvement in the large Axis anti @-@ Partisan offensive Case White alongside Italian troops . In 1944 , he became a leader of the Chetnik forces in Herzegovina , and along with Dobroslav Jevđević was involved in attempts to come to terms with the Allied forces . In late 1944 , as the Partisans tightened their grip on the country and the Soviet Red Army captured Belgrade , he re @-@ joined Mihailović in northeastern Bosnia but they could not agree on what course of action to take . Ostojić , along with Chetnik leaders Pavle Đurišić and Petar Baćović and Chetnik ideologue Dragiša Vasić decided to move west to the area of the Ljubljana Gap in modern @-@ day Slovenia where other friendly forces were concentrating . In early April 1945 , faced with attacks by the Partisans and the Armed Forces of the Independent State of Croatia ( HOS ) along their route , the combined Chetnik force was defeated by HOS forces in the Battle of Lijevče Field , after which Ostojić was captured by the Ustaše in an apparent trap . According to some sources , he was killed in the Jasenovac concentration camp alongside Đurišić , Baćović and Vasić . 
