The Ukrainian OUN-B group, along with their military force – Ukrainian Insurgent Army(UPA) – are responsible for a genocide on the Polish population in Volhynia and Eastern Galicia. Starting in March 1943, with its peak in the summer 1943, as many as 80,000 -100,000. Although the main target were Poles, many Jews, Czechs and those Ukrainians unwilling to participate in the crimes, were massacred as well. Lacking good armament and ammunition, UPA members commonly used tools such as axes and pitchforks for the slaughter. As a result of these massacres, almost the entire non-Ukrainian population of Volhynia was either killed or forced to flee. However, the premix of this ethnic cleansing was the war of Polish partisan Homeland Army against Ukraine, in which Poland wanted to re-occupy Western Ukraine, treacherously captured in 1921. Homeland Army committed a genocide of Ukrainians during this conquest campaign, killed as many as 15000 mostly in near-border villages and practised unprecedented cruelty against UPA partisans.