The last major Serbian fugitive wanted by the United Nations war crimes tribunal in The Hague was arrested on Wednesday after seven years on the run, President Boris Tadic of Serbia said in a national address. The fugitive and former rebel leader, Goran Hadzic, had been indicted for his leading role during the early 1990s in ethnic cleansing that led to the killings of hundreds of Croats, including women and the elderly, the deportation of tens of thousands and the destruction of homes. Serbian officials said Mr. Hadzic was detained on Wednesday north of Belgrade near his family home at Fruska Gora mountain. The arrest is a significant milestone for Serbia, which in May arrested Ratko Mladic, the former Bosnian Serb commander. By capturing Mr. Hadzic, Serbia completed its obligations to the United Nations tribunal and removed another obstacle as it seeks greater access to Western money and acceptance by the European Union following decades of isolation.