Khartoum society, while others settled in large slums at the outskirts of the city. Since the mid-1980s, large numbers of refugees from South Sudan and Darfur fleeing the violence of the Second Sudanese Civil War and Darfur conflict have settled around Khartoum. In 1991, Osama bin Laden purchased a house in the affluent al-Riyadh neighborhood of the city and another in Soba. He lived there until 1996, when he was banished from the country. Following the 1998 U.S. embassy bombings, the United States accused bin Laden's al-Qaeda group and, on 20 August, launched cruise missile attacks on the al-Shifa pharmaceutical factory
Siege of Khartoum to the north by the Blue Nile and to the west by the White Nile. To defend the river banks, he created a flotilla of gunboats from nine small paddle-wheel steamers, until then used for communication purposes, which were fitted with guns and protected by metal plates. In the southern part of the town, which faced the open desert, he prepared an elaborate system of trenches, makeshift Fougasse-type land mines, and wire entanglements. Also, the surrounding country was controlled by the Shagia tribe, which was hostile to the Mahdi. By early April 1884, the tribes north of Khartoum rose in