In the first half of the second millennium A.D., northern Mozambican port towns were frequented by traders from Somalia, Ethiopia, Egypt, Arabia, Persia, and India. The Portuguese were able to wrest much of the coastal trade from Arab Muslims in the centuries after 1500 and to set up their own colonies. Portugal did not relinquish Mozambique until 1975. Large-scale emigration, economic dependence on South Africa, a severe drought, and a prolonged civil war hindered the country's development until the mid-1990s. The ruling Front for the Liberation of Mozambique (FRELIMO) party formally abandoned Marxism in 1989, and a new constitution the following year provided for multiparty elections and a free market economy. A UN-negotiated peace agreement between FRELIMO and rebel Mozambique National Resistance (RENAMO) forces ended the fighting in 1992. In 2004, Mozambique underwent a delicate transition as Joaquim CHISSANO stepped down after 18 years in office. His elected successor, Armando GUEBUZA, served two terms and then passed executive power to Filipe NYUSI in 2015. RENAMO’s residual armed forces intermittently engaged in a low-level insurgency after 2012, but a late December 2016 ceasefire eventually led to the two sides signing a comprehensive peace deal in August 2019. Elections in October 2019, challenged by Western observers and civil society as being problematic, resulted in resounding wins for NYUSI and FRELIMO across the country. Since October 2017, violent extremists - who an official ISIS media outlet recognized as ISIS's network in Mozambique for the first time in June 2019 - have been conducting attacks against civilians and security services in the northern province of Cabo Delgado.