  am ▁after ▁prepar atory ▁art illery ▁fire ▁against ▁V ital j ina ▁and ▁other ▁targets ▁in ▁Kon av le . ▁The ▁advance , ▁using ▁several ▁roads ▁in ▁the ▁region , ▁was ▁supported ▁by ▁the ▁Y ug oslav ▁Navy ▁and ▁the ▁Air ▁Force . ▁Cro at ian ▁def ences ▁were ▁none x istent ▁in ▁Kon av le ▁and ▁light ▁in ▁Dub ro va č ko ▁Prim or je — the ▁only ▁J NA ▁cas ual ties ▁of ▁the ▁day ▁occurred ▁during ▁a ▁successful ▁Z NG ▁amb ush ▁in ▁Č ep iku će ▁village . ▁On ▁the ▁first ▁day ▁of ▁the ▁off ensive , ▁J NA ▁art illery ▁attacked ▁Sr đ ▁Hill ▁and ▁the ▁Ž ark ov ica ▁prom ont ory ▁just ▁to ▁the ▁north ▁and ▁east ▁of ▁Dub rov nik , ▁while ▁Y ug oslav ▁Air ▁Force ▁Mi G - 2 1 s ▁ra ided ▁Kom ol ac ▁in ▁R ije ka ▁Dub ro va čka ▁to ▁the ▁west , ▁destroy ing ▁supplies ▁of ▁electric ity ▁and ▁water ▁to ▁Dub rov nik . ▁Until ▁the ▁end ▁of ▁December , ▁Dub rov nik ▁re lied ▁on ▁fresh ▁water ▁supplied ▁by ▁boats ▁and ▁electric ity ▁from ▁a ▁few ▁electric ▁gener ators . ▁ ▁Over ▁the ▁next ▁three ▁days , ▁the ▁J NA ▁made ▁slow ▁progress . ▁Its ▁art illery ▁attacked ▁Sr đ ▁Hill , ▁the ▁Fort ▁Imperial ▁and ▁Ž ark ov ica ▁on ▁ 2 ▁October . ▁The ▁next ▁day , ▁the ▁J NA ▁sh elled ▁Dub rov nik ' s ▁Bel ved ere ▁Hotel