Thousands of people have fled el-Fasher after Sudan's Darfur city fell to the paramilitary Rapid Support Forces, ending an 18-month siege. Many walked 70 kilometers (about 40 miles) to reach the Tawila refugee camp, escaping severe shortages of food, water and shelter. Survivors recounted the tragedy. "I've lost my mother and three brothers," Najwa Adam said. "I don't know where they are." Aid agencies warn that thousands remain trapped in el-Fasher. As reports of executions, sexual violence and looting continue, the United Nations is calling for urgent investigations and justice.