An airman from the Emirati armed forces gives a colleague a bullet during a flight from a base in Saudi Arabia to the frontline Yemeni province of Mareb September 14, 2015. Gulf Arab coalition forces fighting Houthi militia in Yemen are advancing on the capital in a two-pronged offensive, generals told reporters on Monday at a desert oil compound they have turned into a military base. Picture taken September 14, 2015. REUTERS/Noah Browning