The first Serbian Republic and the Montenegrin republic composed the Federal Republic of Yugoslavia during the breakup of Yugoslavia. Montenegro remained a part of Yugoslavia after an overwhelming majority of the population voted for unity with Serbia in 1992. In the Yugoslav Wars, Montenegrin forces notably led the Siege of Dubrovnik. Radovan Karadžić, former war-time president of Republika Srpska, is often mistaken as a Bosnian Serb—he was in fact an ethnic Drobnjak who was born in Šavnik. He was known to have supported a united state between Republika Srpska, Serbia, and Montenegro. Throughout his mandate, Yugoslav president Slobodan Milošević appointed several Montenegrin politicians like Milo Đukanović and Svetozar Marović who would cooperate with his regime to a great degree and then denounce him years later. On February 4, 2003, the Federal Republic of Yugoslavia changed its name to Serbia and Montenegro. The Constitutional Charter of Serbia and Montenegro, the amended constitution of the previous Federal Republic, allowed either of the two member states to hold an independence referendum once every three years. After the assassination of Zoran Đinđić on March 12, 2003, a massive police operation dubbed Operation Sabre was undertaken by the government of Serbia and Montenegro in which various locations in Montenegro (particularly Budva) were investigated due to previous assassination attempts originating from there.