Before World War II, Poland's Jewish community had numbered between 3,300,000 and 3,500,000 people – about 10 percent of the country's total population. Following the invasion of Poland, Germany's Nazi regime sent millions of deportees from every European country to the concentration and forced-labor camps set up in the General Government territory of occupied Poland and across the Polish areas annexed by Nazi Germany. Most Jews were imprisoned in the Nazi ghettos, which they were forbidden to leave. Soon after the German–Soviet war had broken out in 1941, the Germans began their extermination of Polish Jews on either side of the Curzon Line, parallel to the ethnic cleansing of the Polish population including Romani and other minorities of Poland.