High Quality Content by WIKIPEDIA articles! During World War II, the Croatian Usta e regime murdered between 56,000 and 97,000 people in Jasenovac concentration camp, predominantly Serbs, but also Bosniaks (Bosnian Muslims), Jews, and Roma. Following the invasion of the Kingdom of Yugoslavia in 1941, the Kingdom was divided into several occupation zones. A rump Serbia remained, following the country's dismemberment. Under its leader Ante Paveli , the Usta a subjected ethnic Serbs, together with much smaller minorities of Jews and Roma, to a campaign of genocidal persecution. It is estimated that, during WWII, between 500,000 and 1,200,000 Serbs were killed. Of that number, according to the United States Holocaust Memorial Museum, the Usta e killed 330,000 390,000 ethnic Serbs in Bosnia and Herzegovina and Croatia.