Jewish Combat Organization
Together with Arie Wilner, Klepfisz also served as an intermediary between the Jewish Combat Organization and the Polish resistance movement organisation - Home Army. He was trained in explosives production by a Home Army soldier, Zbigniew Lewandowski ("nom de guerre" "Szyna"—"Rail"). Klepfisz, Wilner and Icchak Cukierman, through the AK, and through the AK-subordinated Polish Socialist Party,WRN (Polish Socialists not associated with Moscow) sent arms into the Ghetto.