Anti-Serb riots in Sarajevo
Anti-Serb riots, consisting of large-scale violence against Serbs, occurred in Sarajevo on 28 and 29 June 1914 after the assassination of Archduke Franz Ferdinand. Encouraged by the Austro-Hungarian government, the violent demonstrations assumed the characteristics of a pogrom, which led to ethnic divisions that were unprecedented in the city's history.
Source: Wikipedia — Anti-Serb riots in Sarajevo (CC BY-SA 4.0)