carry pilgrims, was not only important for Ottoman communications but contained solidly-built stone station buildings which could form defensive positions. With the balance of power in northern Sinai moving in favour of the British, the Sherif was encouraged to seek support for his revolt from as far north as Baalbek, north of Damascus. In London, the War Office, hoping to foment unrest throughout the Ottoman Arab territories, encouraged Murray's plan to advance to El Arish. Sinai campaign of manoeuvre warfare At the conclusion of the Battle of Romani on 12 August 1916, the Ottoman Army had been pushed back to its forward position at Bir el Abd, the last oasis in the series stretching from the Romani area. The Ottomans' main forward base was pushed back to El Arish, with a fortified advanced post at Bir el Mazar, where a small group of wells which reliably provided water. El Arish was the target of an air raid on 18 June 1916 by 11 aircraft of the 5th Wing under Colonel W. G. H. Salmond. The planes flew out to sea until east of El Arish, then turned inland to approach from the southeast. Two Ottoman aircraft on the ground and two of the ten aircraft hangars were set on fire; bombs hit four others and troops were also attacked. Three British aircraft were forced to land, one in the sea. The Egyptian Expeditionary Force required huge amounts of ammunition and supplies and a reliable source of water for an advance to El Arish. To provide this, the British Royal Engineers built a railway and pipeline across the Sinai Peninsula to El Arish under the leadership of Brigadier-General Everard Blair. From the middle of August to the Battle for Magdhaba on 23 December 1916, British forces waited for this necessary infrastructure to be put in place. These four months have often been described as a period of rest for the Anzac Mounted Division as there were no major battles. However, the mounted troops were busy providing screens for the construction, patrolling newly occupied areas and carrying out reconnaissances to augment aerial photographs to improve maps of the newly occupied areas. During one of the patrols, on 19 August, a group of 68 Ottoman soldiers was found half dead from thirst by the 5th Light Horse Regiment (2nd Light Horse Brigade) who, rather than attacking them, gave them water and their rides.