 After 5 days of fierce urban warfare, Port Harcourt fell to the Nigerian 3rd Division under Gen. Adekunle while the Biafran 52nd Brigade was forced to retreat to Igrita.After being relieved of his command by Ojukwu, Kalu was made commander of the Biafran 63rd Brigade and staged a successful assault behind enemy lines after crossing the Niger River under the cover of darkness.The 63rd Brigade staged attacks against Nigerian 2nd Division soldiers stationed in Asaba, Ogwashi-Uku, and Igbuzo.