On April 1, 1933, the Nazis instigated their first action against Jews by announcing a boycott of all Jewish-run businesses. The Nuremberg Laws, issued on September 15, 1935, began to exclude Jews from public life. The Nuremberg Laws included a law that stripped German Jews of their citizenship and a law that prohibited marriages and any sex or relationships between Jews and Germans. During the night of November 9 1938, Nazis incited a pogrom (violent mob attack) against Jews in Austria and Germany in what has been termed, "Kristallnacht" (Night of Broken Glass). This night of violence included the pillaging and burning of Jewish synagogues, breaking the windows of Jewish-owned businesses, looting stores, and many Jews were physically attacked. Approximately 30,000 Jews were arrested and sent to concentration camps. After World War II started in 1939, the Nazis began ordering Jews to wear a yellow Star of David on their clothing so that Jews could be easily recognized and targeted. Homosexuals had to wear pink inverted triangles and Jehovah’s Witnesses wore purple ones. Criminals wore green triangles, Roma and other groups wore black or brown. Although many people refer to all Nazi camps as "concentration camps," there were actually a number of different kinds of camps, including concentration camps, extermination camps, labor camps, prisoner-of-war camps, and transit camps. One of the first concentration camps was