Charges that hundreds of civilians were being “systematically killed” in the Sierra Maestra region by Government airplanes were made yesterday by representatives of Fidel Castro’s insurgents.

Dr. Mario Llerena, chief Castro representative abroad, said the people of the mountain area, more than 10,000 families were being attacked with fire bombs and machine guns. Houses, crops and cattle are also being destroyed in an attempt to deter local aid to rebels, he declared.