 The growing unrest in Portugal culminated on April 25 , 1974 , when the Carnation Revolution , a peaceful leftist military coup d 'état in Lisbon , ousted the incumbent Portuguese government of Marcelo <unk> . Thousands of Portuguese citizens left Mozambique , and the new head of government , General António de <unk> , called for a ceasefire . With the change of government in Lisbon , many soldiers refused to continue fighting , often remaining in their barracks instead of going on patrol . Negotiations between the Portuguese administration culminated in the <unk> <unk> signed on September 7 , 1974 , which provided for a complete hand @-@ over of power to FRELIMO , uncontested by elections . Formal independence was set for June 25 , 1975 , the 13th anniversary of the founding of FRELIMO . 
