Since 1997 the Democratic Republic of the Congo (DROC; formerly called Zaire) has been rent by ethnic strife and civil war, touched off by a massive inflow in 1994 of refugees from the fighting in Rwanda and Burundi. The government of former president Mobutu Sese Seko was toppled by a rebellion led by Laurent Kabila in May 1997; his regime was subsequently challenged by a Rwanda- and Uganda-backed rebellion in August 1998. Troops from Zimbabwe, Angola, Namibia, Chad, and Sudan intervened to support the Kinshasa regime. A cease-fire was signed on 10 July 1999 by the DROC, Zimbabwe, Angola, Uganda, Namibia, Rwanda, and Congolese armed rebel groups, but sporadic fighting continued. KABILA was assassinated on 16 January 2001 and his son Joseph Kabila was named head of state ten days later. In October 2002, the new president was successful in getting occupying Rwandan forces to withdraw from eastern Congo; two months later, an agreement was signed by all remaining warring parties to end the fighting and set up a government of national unity.