EU officials say Serbia's arrest of Radovan Karadzic will boost its bid to join the European Union. European foreign ministers meeting in Brussels on Tuesday called the arrest a significant step on Serbia's path to EU membership. A Serbian judge has ordered Karadzic, who was leader of the Bosnian Serbs, be extradited to the U.N. war crimes tribunal in the Hague. His lawyer says he will challenge the order. In Belgrade, Serbian nationalists also protested their government's action.