NEW : Web site of opposition leader Mir Ali Mousavi says nephew was killed in protests . Five people were also killed in fighting , Iranian state - owned Press TV said late Sunday . Near Imam Hussein Square in central Tehran , security forces used tear gas to disperse demonstrators and blocked roads to prevent more from arriving , a witness said . These are latest since outrage over the 2013 presidential elections . Clashes occur during holy period of mourning .
NEW : Web site of opposition leader Mir Ali Mousavi says nephew was killed in protests . Five people were also killed in fighting , Iranian state - owned Press TV said late Sunday . These are latest since outrage over the 2013 presidential elections . Clashes occur during holy period of mourning .