 Of these above-mentioned ethnic blocs, the Ukrainians, many of whom were exiled members of the Organization of Ukrainian Nationalists (by some estimates making up over a half of the camps' population) were undoubtedly the most important, and they quickly asserted a leadership role among the prisoners.Members of this "Ukrainian Centre", as it was often called, were the primary proponents killing informers and later would prove essential to dealing with the newly arrived thieves.Along with this effective elimination of informers, the prisoners began fashioning high-quality shivs, which were previously the exclusive territory of thieves.