An estimated 125,000 people, including more than 57,000 children, have fled since hostilities erupted in July between the Iran-backed Houthi rebels, the Yemeni government and its ally Saudi Arabia, with the UN calling it one of the most rapid and volatile waves of displacement in Yemen in years. Thousands have even been making the dangerous crossing across the Bab el-Mandeb strait to Djibouti, many of them children, travelling in extreme heat, often without enough water.