Ethnic Serbs were targeted by the genocidal policies of the Ustaše-led Independent State of Croatia, a puppet state of Nazi Germany which was established after the Axis invasion of Yugoslavia. The massacre of Serbs by the local Ustaše, such as those in July and early August 1941 in villages around Kulen Vakuf, led to reprisals. The retaliation was brief and quickly repressed, unlike Ustaše war crimes (which were organized at the top of the Croatian government in Zagreb, which systematically and persistently pushed the local Ustaše to commit massacres. The description of the events as conflicts between local Chetniks and Ustaše, motivated by ethnic intolerance, has been called an oversimplification.