Until 1960, Portuguese military forces serving in Guinea were composed of units led by white officers, with commissioned soldiers (whites), overseas soldiers (African assimilados), and native or indigenous Africans (indigenato) serving in the enlisted ranks. General Spínola's Africanization policy eliminated these discriminatory colour bars, and called for the integration of indigenous Guinea Africans into Portuguese military forces in Africa. Two special indigenous African counterinsurgency detachments were formed by the Portuguese Armed Forces. The first of these was the African Commandos ("Comandos Africanos"), consisting of a battalion of commandos composed entirely of black soldiers (including the officers). The second was the African Special Marines ("Fuzileiros Especiais Africanos"), Marine units entirely composed of black soldiers. The African Special Marines supplemented other Portuguese elite units conducting amphibious operations in the riverine areas of Guinea in an attempt to interdict and destroy guerrilla forces and supplies. General Spínola's Africanization policy also fostered a large increase in indigenous recruitment into the armed forces, culminating the establishment of all-black military formations such as the Black Militias ("Milícias negras") commanded by Major Carlos Fabião. By the early 1970s, an increasing percentage of Guineans were serving as noncommissioned or commissioned officers in Portuguese military forces in Africa, including such higher-ranking officers as Captain (later Lt. Colonel) Marcelino da Mata, a black Portuguese citizen born of Guinean parents who rose from a first sergeant in a road engineering unit to a commander in the "Comandos Africanos".