▁respond ▁to ▁the ▁call - up . ▁On ▁ 1 8 ▁September , ▁ Đ uk an ović ▁threatened ▁har sh ▁pun ishment ▁of ▁deser ters ▁and ▁those ▁ref using ▁to ▁respond ▁to ▁the ▁mobil ization . ▁The ▁mobil ization ▁and ▁the ▁propag anda ▁were ▁ ▁in ▁contrast ▁with ▁ass ur ances ▁from ▁Y ug oslav ▁federal ▁authorities ▁in ▁Bel grade ▁that ▁there ▁would ▁be ▁no ▁attack ▁against ▁Dub rov nik . ▁The ▁J NA ' s ▁strateg ic ▁plan ▁to ▁defeat ▁Cro atia ▁included ▁an ▁off ensive ▁to ▁cut ▁off ▁the ▁southern most ▁parts ▁of ▁Cro atia , ▁including ▁Dub rov nik , ▁from ▁the ▁rest ▁of ▁the ▁country . ▁ ▁On ▁ 2 3 ▁September , ▁J NA ▁art illery ▁attacked ▁the ▁village ▁of ▁V ital j ina ▁in ▁the ▁eastern ▁part ▁of ▁Kon av le ▁and ▁Br gat ▁to ▁the ▁east ▁of ▁Dub rov nik . ▁Two ▁days ▁later , ▁the ▁Y ug oslav ▁Navy ▁block aded ▁mar itime ▁routes ▁to ▁the ▁city . ▁On ▁ 2 6 ▁September , ▁the ▁J NA ▁renamed ▁its ▁Eastern ▁Herz egov ina ▁Oper ational ▁Group ▁the ▁ 2 nd ▁Oper ational ▁Group ▁and ▁sub ordin ated ▁it ▁directly ▁to ▁the ▁Federal ▁Ministry ▁of ▁Def ence ▁and ▁the ▁J NA ▁General ▁Staff . ▁C ok ić ▁was ▁appointed ▁the ▁first ▁command ing ▁officer ▁of ▁the ▁ 2 nd ▁Oper ational ▁Group ▁but ▁was ▁replaced ▁by ▁General ▁M ile ▁Ru ž in ov ski ▁on ▁ 5 ▁October ▁following ▁the ▁shooting ▁down ▁of ▁C ok