SECURITY FORCES in Bangladesh opened fire Saturday on demonstrators demanding the resignation of President Hussain Muhammad Ershad, killing nine people, according to reports reaching India . . . ACTOR PIERRE DUX, one of the century's great French classical performers and former head of the prestigious Comedie Francaise, died Saturday in Paris at age 83 . . . CARDINAL AGOSTINO CASAROLI, the Vatican's No. 2 official whose cautious diplomacy helped the church survive in Eastern Europe during Cold War years, retired Saturday after four decades of papal service.