The insurgency in Mozambique began in the extreme northern areas of the province in 1964 and was led by guerrilla forces of the Front for the Liberation of Mozambique (Frente de Libertação de Moçambique--FRELIMO). FRELIMO was well armed by various communist countries, and its fighters were trained by the Chinese. At the time of the outbreak of hostilities, Portugal had about 16,000 troops in the province, all deployed in the north where the FRELIMO attacks were concentrated. For several years, Portuguese forces were able to prevent the guerrillas from moving southward. They could not end the warfare, however, because the guerrillas had a sanctuary to which they could retreat and a constant source of arms. Eventually the guerrillas were able to skirt the Portuguese strength in the north and mount incursions into the relatively unprotected center.

Of the 60,000 government troops ultimately involved in Mozambique, 35,000 were black Africans, 10,000 were white Africans, and the remaining 15,000 were from Portugal. This relatively large force faced approximately 8,000 insurgents. Despite this numerical superiority, the Portuguese government was unable to counter the guerrillas' tactics, which included ambushes, selective terrorism, and severing road and rail links. By September 1975, when the former province became independent as the People's Republic of Mozambique, Portuguese losses were officially reported as 1,606 killed in action and 724 noncombat deaths.

Data as of January 1993