Rollkommando Hamann () was a small mobile unit that committed mass murders of Lithuanian Jews in the countryside in July–October 1941, with an estimated death toll of at least 60,000 Jews. The unit was also responsible for many murders in Latvia from July through August, 1941. At the end of 1941 the destruction of Lithuanian Jewry was effectively accomplished by Hamann's unit in the countryside, by the Ypatingasis būrys in the Ponary massacre, and by the Tautinio Darbo Apsaugos Batalionas (TDA) in the Ninth Fort in Kaunas. In about six months an estimated 80% of all Lithuanian Jews were killed. The remaining few were spared for use as a labor force and concentrated in urban ghettos, mainly the Vilna and Kaunas Ghettos.