Angola, officially the Republic of Angola, is a country in south-central Africa bordering Namibia to the south, Democratic Republic of the Congo to the north, and Zambia to the east, and with a west coast along the Atlantic Ocean. The exclave province Cabinda has a border with the Republic of the Congo and the Democratic Republic of the Congo. Angola was a Portuguese colony from the 16th century to 1975. The country is the second-largest petroleum and diamond producer in sub-Saharan Africa, yet its people are among the continent's poorest. According to the International Monetary Fund, more than $4 billion in oil receipts have disappeared from Angola's treasury in the 2000s. In August 2006, a peace deal was signed with a faction of the FLEC, a separatist guerrilla from the Cabinda exclave in the North, which is still active. About 65% of Angola's oil comes from that region.