 Tung also headed a group run by the CIA , in which ARVN personnel of northern origin infiltrated North Vietnam , posing as locals . The objective was to gather intelligence and sabotage communist infrastructure and communications facilities . The recruits were trained in bases at Nha Trang , Đà Nẵng , and sometimes offshore in Taiwan , Guam and Okinawa . Around eighty groups of operatives , each numbering six or seven men , were deployed in 1963 . They entered the north via parachute drops or sampan journeys at night , but nearly all were captured or killed . The captives were frequently used in communist propaganda broadcasts . Tung was criticised for his management of the operations . 
