Before 1939 about 7,000 people lived in Maków, including 4,000 Poles and 3,000 Jews. During the German invasion of Poland, which started World War II, the "Einsatzgruppe V" entered the town on September 10–11, 1939, commit atrocities against the population. The "Einsatzgruppe V" immediately carried out searches of Polish offices and organizations. Medicines from pharmacies and local supplies of grain, sugar and rice were confiscated for the German Army. Under German occupation the name was Germanized to "Mackeim". In Maków, the Germans operated a concentration camp for ill and disabled people from the region. In February 1940, the Germans murdered 560 people from the camp in a forest near Wyszogród, while 50 people from the local hospital were murdered in the nearby village of Grzanka. The Jewish community was murdered by Nazi Germany in the Holocaust. Some killings were done in the town; thousands of Maków Mazowiecki Jews were murdered at the Auschwitz concentration camp. The Germans also operated a forced labour camp in the town from 1941 to 1944.