Demographics of Mozambique are dominant in the northern part of the country — the Sena and Shona (mostly Ndau) are prominent in the Zambezi valley, and the Shangaan (Tsonga) dominate in southern Mozambique. Other groups include Makonde, Yao, Swahili, Tonga, Chopi, and Nguni (including Zulu). The country is also home to a growing number of white residents, most with Portuguese ancestry. During colonial rule, European residents hailed from every Mozambican province, and at the time of independence the total population was estimated at around 360,000. Most vacated the region after independence in 1975, emigrating to Portugal as "retornados". There is also a larger
People's Republic of Mozambique preceding independence, FRELIMO consolidated its presence in the south and in urban areas. This was done through the work of militant groups ("grupos dinamizadores" or "dynamic groups"), which also included Mozambicans of Portuguese origin. The period prior to independence was also marked by the settling of scores and public trials against members FRELIMO who had strayed from the FRELIMO party line. "Traitors," "reactionaries," and real or suspected agents of the U.S. Central Intelligence Agency or PIDE, the Portuguese security agency. The Central Committee of FRELIMO adopted the constitution of the People's Republic of Mozambique on June 20, which established that