A Nazi ghetto was established in Irena in November 1940 or early 1941, probably on the orders of Kurt Lenk, the region's new land commissioner. Some Jews were forced to move from their homes to the ghetto. The motive was probably to keep Jews away from the two nearby military installations, a Luftwaffe airfield and a German Army base, which were filled with troops in preparation for the 1941 invasion of the Soviet Union. The decree establishing the ghetto was not formally issued until 1942. Until 1942, Irena was an open ghetto (there was no physical fence, although the penalty for unauthorized departure was death) consisting of six streets. Its boundaries were initially Okólna Street, the Irenka River, Bankowa, and Staromiejska Streets. Staromiejska Street was removed from the ghetto in September 1942; its residents moved to Bankowa. Initially, non-Jews were allowed to enter and perhaps live in the ghetto, so many of the Jews were able to survive by trading material goods for food with them. A Polish-language secular school, run by Aida Milgroijm-Citronbojm, instructed 70 to 100 pupils. The Jewish Ghetto Police maintained order in the ghetto, and on the outside it was guarded by a ("Special Services") unit consisting of local (ethnic Germans) and Ukrainian Auxiliary Police. The unit was known for beating, humiliating, and killing ghetto inmates.