▁suppress ed ▁the ▁organisation ▁in ▁Lith u ania . ▁ ▁Host ilities ▁over ▁the ▁Su w ał ki ▁Region ▁res umed ▁in ▁summer ▁ 1 9 2 0 . ▁When ▁the ▁Polish ▁Army ▁began ▁to ▁retre at ▁during ▁the ▁course ▁of ▁the ▁Polish – S ov iet ▁War , ▁the ▁Lith u ani ans ▁moved ▁to ▁secure ▁what ▁they ▁claimed ▁to ▁be ▁their ▁new ▁borders , ▁set ▁by ▁the ▁Soviet – L ith uan ian ▁Peace ▁Tre aty ▁of ▁July ▁ 1 9 2 0 . ▁The ▁Peace ▁Tre aty ▁granted ▁Se j ny ▁and ▁surrounding ▁area ▁to ▁Lith u ania . ▁Poland ▁did ▁not ▁recognize ▁this ▁bil ater al ▁treat y . ▁En su ing ▁t ensions ▁height ened ▁until ▁the ▁out break ▁of ▁the ▁Polish – L ith uan ian ▁War . ▁Se j ny ▁changed ▁hands ▁frequently ▁until ▁it ▁was ▁controlled ▁by ▁Polish ▁forces ▁on ▁September ▁ 2 2 , ▁ 1 9 2 0 . ▁The ▁situation ▁was ▁legal ized ▁by ▁the ▁Su w ał ki ▁Ag re ement ▁of ▁October ▁ 7 , ▁ 1 9 2 0 , ▁which ▁effectively ▁returned ▁the ▁town ▁to ▁the ▁Polish ▁side ▁of ▁the ▁border . ▁ ▁Notes ▁ ▁References ▁▁▁▁▁▁▁▁ ▁Category : Conf lic ts ▁in ▁ 1 9 1 9 ▁Category : L ith u ania – Pol and ▁relations ▁Category : R eb ell ions ▁in ▁Poland ▁Category : 1 9 1 9 ▁in ▁Lith u ania ▁Category : 1 9 1 9 ▁in ▁Poland ▁Category : 2 0