 No serious fighting took place on 11 August , but von Kressenstein 's force at Bir el Abd was watched and harassed , and plans were made for an attack on 12 August . The advance of the Anzac Mounted Division began at daylight , but soon afterwards , forward patrols reported that the garrison at Bir el Abd was retiring . The mounted force followed the Austrians , Germans and Ottomans as far as Salmana , where another rearguard action delayed the mounted force , as the enemy withdrawal continued back to El Arish . 
