Concentration camp, prison for the detention of political or military suspects, frequently found in totalitarian countries and sometimes in democratic nations during time of war. Concentration camps differ sharply from other prisons in the absence of regular judicial proceedings and the fact that prisoners may be held indefinitely. Camps have often served to confine large segments of the population felt to be dangerous to the government. During World War II the United States placed several thousands of its Japanese-American citizens in camps until the end of the war. The most notorious concentration camps were those maintained by the Nazi regime in Germany before and during World War II. Jews and a minority of nationals from occupied countries performed hard manual labor in a semistarved state. Those unwanted or unfit to work were sent to extermination centers to be gassed and afterward burned in incinerators. Sadism and torture were practiced in these camps. More than 6 million men, women, and children died in the German concentration camps, of which the largest were at Auschwitz, Dachau, Buchenwald, and Belsen.