During the 1976-1983 Argentine Dirty War, many thousands of people disappeared, clandestinely kidnapped by groups acting for the dictatorship. Human rights groups in Argentina often cite a figure of 30,000 disappeared; Amnesty International estimates 20,000. Many were killed in death flights, a practice initiated by Admiral Luis María Mendía, usually after detention and torture. Typically they were drugged into a stupor, loaded into aircraft, stripped, and dropped into the Río de la Plata or the Atlantic Ocean.