Economy During British rule, economic development in South Yemen was restricted to the city of Aden, focused mainly on the port and on the British military bases. As a result, following the British withdrawal, there here was little to no industrial output or mineral wealth exploitation in the country until the mid-1980s, when significant petroleum reserves in the central regions near Shibam and Mukalla were discovered. Foreign aid was minimal, as the British government did not fulfill promises of aid and the Soviet Union offered only US$152 million from 1969 to 1980. The main sources of income were agriculture, mostly fruit, cereal crops, cattle and sheep, and fishing. The government guaranteed full employment in agriculture for rural citizens, and established a number of collective farms, however, those set up following the Soviet model produced poorer results than cooperative-run farms. The national budget was 13.43 million dinars in 1976, and the gross national product was US$150 million. The total national debt was $52.4 million. Airlines The following airlines had operated from the PDRY: Aden Airways (1949–1967). Ceased operations on 30 June 1967 at the time of British withdrawal from the Federation and the Protectorate of South Arabia. Alyemda – Democratic Yemen Airlines (1961–1996). Joined Yemenia, the airline of the former YAR Yemen Airways (1989–1990) Movements to revive South Yemen Since 2007, some Southerners have been actively protesting for independence, in a movement known as 'Al Hirak' or the Southern Movement. During the Yemen Civil War, in response to incursions by the Houthis and military forces loyal to deposed Yemeni president Ali Abdullah Saleh, members of the Southern Movement formed 'Popular Resistance' militias. Since the Battle of Aden, these armed groups have sought to defend the South against Houthi/Saleh attempts to take over the country and have used civil war as an opportunity to further their struggle for independence. In late January 2018, separatists loyal to the Southern Transitional Council seized control of the Saudi-backed Yemeni government headquarters in Aden in an apparent coup d'état against the Hadi government. See also List of leaders of South Yemen History of Yemen Democratic Republic of Yemen South Yemen Movement South Yemen insurgency Dhofar Rebellion Yemen References External links South Yemen Anthem (1969–1979), National anthem of Yemen (second and last anthem of South Yemen) Yemen Yemen Communism in Yemen Yemen Yemen Yemen Yemen Atheist states Yemen Yemen