Belgrade - Opposition leaders in Yugoslavia have announced their first joint rally, a sign that the campaign to remove Mr Slobodan Milosevic as president is moving into its next phase. The demonstration was announced by Mr Mladjan Dinkic (35), leader of the Group 17 organisation of independent Yugoslav economists. He hopes to bring together the two main opposition figures, Mr Vuk Draskovic of the Serbian Renewal Movement and Mr Zoran Djindjic of Serbia's Democratic party.