- day ▁Lith u ania – Pol and ▁border . ▁ ▁On ▁July ▁ 2 6 , ▁the ▁F och ▁Line ▁was ▁accepted ▁by ▁the ▁Conference ▁of ▁Amb ass adors ▁as ▁the ▁prov is ional ▁border ▁between ▁the ▁two ▁states . ▁Lith u ani ans ▁were ▁not ▁informed ▁about ▁this ▁decision ▁until ▁August ▁ 3 . ▁Ne ither ▁country ▁was ▁satisfied : ▁both ▁Lith uan ian ▁and ▁Polish ▁forces ▁would ▁have ▁to ▁retre at ▁from ▁the ▁Su w ał ki ▁and ▁Vil nius ▁regions , ▁respectively . ▁Those ▁Germ ans ▁still ▁present ▁in ▁the ▁region ▁also ▁object ed ▁to ▁the ▁boundary ▁of ▁the ▁line . ▁The ▁Lith uan ian ▁forces ▁( about ▁ 3 5 0 ▁strong ) ▁left ▁the ▁town ▁of ▁Su w ał ki ▁by ▁August ▁ 7 , ▁but ▁stopped ▁in ▁Se j ny ▁and ▁formed ▁a ▁line ▁at ▁the ▁Cz arna ▁Ha ń cza ▁river ▁– ▁W ig ry ▁Lake , ▁thus ▁effectively ▁viol ating ▁the ▁dem arc ation ▁line . ▁Lith u ani ans ▁believed ▁that ▁the ▁F och ▁Line ▁was ▁not ▁the ▁final ▁decision , ▁and ▁that ▁they ▁had ▁the ▁duty ▁to ▁protect ▁Lith uan ian ▁out posts ▁in ▁the ▁region . ▁ ▁U pr ising ▁prepar ations ▁On ▁August ▁ 1 2 , ▁ 1 9 1 9 , ▁two ▁days ▁after ▁the ▁Germ ans ▁retre ated ▁from ▁Se j ny , ▁a ▁Polish ▁meeting ▁in ▁the ▁town ▁attract ed ▁over ▁ 1 0 0 ▁deleg ates ▁from ▁neighbor ing ▁Polish ▁communities ; ▁the ▁meeting ▁passed