Related Rule
Colombia
Practice Relating to Rule 128. Release and Return of Persons Deprived of Their Liberty
Colombia’s Basic Military Manual (1995) provides that all prisoners of war must be repatriated at the end of hostilities. 
Colombia, Derecho Internacional Humanitario – Manual Básico para las Personerías y las Fuerzas Armadas de Colombia, Ministerio de Defensa Nacional, 1995, p. 31.
The Report on the Practice of Colombia states:
The Colombian Government has ordered the demilitarization of certain regions of the country in order to advance dialogue conducive to the demobilization and reintegration of guerrilla groups and also to carry out humanitarian operations, such as those designed to secure the release of persons deprived of liberty, both military and civilian. 
Report on the Practice of Colombia, 1998, Chapter 1.8, referring to President’s Office, Second Report on the Peace Process, 18 May 1995, pp. 3, 11 and 12; Circular of the Major General Miguel Vega Uribe, Commander of the Colombian Armed Forces, reprinted in Arturo Alape, La paz, la violencia: testigos de excepción, Bogotá, Editorial Planeta, 1985, pp. 503–508.
The Report on the Practice of Colombia states:
The release and return of persons deprived of their liberty in the Colombian armed conflict are customarily guaranteed by the ICRC and sometimes other civilian social organizations such as the Church, State-controlled bodies, and journalists, subject to an accord between the parties or the exercise of the ICRC’s right of initiative. 
Report on the Practice of Colombia, 1998, Chapter 5.4.
In 1997, according to the report:
To obtain the release of 70 soldiers, the Government and the guerrillas agreed to the demilitarization of an area measuring 13,161 square kilometres in the department of Caquetá. To guarantee the suspension of military operations so that the soldiers could be handed over, the two sides agreed to the presence in the demilitarized zone of representatives of the ICRC, the National Conciliation Commission, the national Government and other competent bodies. 
Report on the Practice of Colombia, 1998, Chapter 1.8, referring to the Agreement of Remolinos de Caguán, 3 June 1997, reprinted in El Colombiano, 4 June 1997, p. 5B.