Sebou River
The chronicler Ibn Khaldun claims Khalid ibn Abi Obeida encountered the Berber forces and held his position at the 'Shalif' river, which many commentators have taken to be the well-known Chelif river ("Wadi ash-Shalif") in central Algeria. However, it is highly improbable that the Berber rebel army would have been that far east by then. Modern historians have suggested Ibn Khaldun or his transcribers made a mistake here. Julien (1961: p. 30) suggests Ibn Khaldun actually meant to say the Sebou River, whose upper reaches would indeed appropriately place the Ifriqiyan column close to Tangiers. The chronicler En-Nuweri indeed reports the skirmish was outside the walls of Tangiers.