Upon taking power Castillo Armas, worried that he lacked popular support, attempted to eliminate all opposition. He quickly arrested many thousands of opposition leaders, branding them communists. Detention camps were built to hold the prisoners when the jails exceeded their capacity. Historians have estimated that more than 3,000 people were arrested following the coup, and that approximately 1,000 agricultural workers were killed by Castillo Armas's troops in Tiquisate. Acting on the advice of Dulles, Castillo Armas also detained a number of citizens trying to flee the country. He also created a National Committee of Defense Against Communism (CDNCC), with sweeping powers of arrest, detention, and deportation. Over the next few years, the committee investigated nearly 70,000 people. Many were imprisoned, executed, or "disappeared", frequently without trial.