آبا
Mohammed Rauf Pasha sent a small party to arrest the Mahdi on Aba Island, but on 11 August 1881 it was overwhelmed, and the insurrection on the southern Sudan began to grow. Rauf Pasha downplayed the "affray" in his report to Cairo, and sent the governor of Kordofan to Aba Island with 1,000 soldiers to crush the Mahdi. When they arrived, they found the Mahdi had fled to the southwest. The soldiers marched after him, but gave up the pursuit when the September rains flooded the roads and riverbeds; they returned to El-Obeid. The Mahdi established a new base in the Nuba Mountains.