▁the ▁administration ▁to ▁local ▁Lith uan ian ▁authorities . ▁Lith uan ian ▁officers ▁and ▁troops , ▁who ▁first ▁arrived ▁in ▁the ▁region ▁in ▁May , ▁began ▁to ▁organ ize ▁military ▁units ▁in ▁the ▁pre - war ▁Se j ny ▁county . ▁ ▁According ▁to ▁Russian ▁statistics ▁from ▁ 1 8 8 9 , ▁there ▁were ▁ 5 7 . 8 % ▁Lith u ani ans , ▁ 1 9 . 1 % ▁Pol es , ▁and ▁ 3 . 5 % ▁Bel arus ians ▁in ▁the ▁Su w ał ki ▁Governor ate . ▁It ▁is ▁generally ▁agreed ▁that ▁Lith u ani ans ▁formed ▁the ▁majority ▁of ▁the ▁population ▁in ▁the ▁northern ▁Su w ał ki ▁Governor ate , ▁while ▁Pol es ▁were ▁concentr ated ▁in ▁the ▁south . ▁But ▁Lith uan ian ▁and ▁Polish ▁histor ians ▁and ▁political ▁scient ists ▁continued ▁to ▁disag ree ▁over ▁the ▁location ▁of ▁the ▁line ▁that ▁separated ▁the ▁areas ▁of ▁Lith uan ian ▁and ▁Polish ▁major ities . ▁Lith u ani ans ▁claimed ▁that ▁Se j ny ▁and ▁the ▁surrounding ▁area ▁were ▁inhab ited ▁primarily ▁by ▁the ▁Lith u ani ans , ▁while ▁the ▁Pol es ▁claimed ▁exactly ▁the ▁opposite . ▁The ▁German ▁census ▁of ▁ 1 9 1 6 ▁showed ▁that ▁ 5 1 % ▁of ▁Se j ny ▁population ▁was ▁Lith uan ian . ▁ ▁Dem arc ation ▁lines ▁ ▁In ▁the ▁after math ▁of ▁World ▁War ▁I , ▁the ▁Conference ▁of ▁Amb ass adors ▁drew ▁the ▁first ▁dem arc ation ▁line ▁between ▁Poland ▁and ▁Lith