Palestinian Muslim worshipers perform "Taraweeh", nightly prayer of the month of Ramadan, at El Khalidi mosque, in Gaza city, on May 27, 2017. Ramadan is sacred to Muslims because it is during that month that tradition says the Koran was revealed to the Prophet Mohammed. The fast is one of the five main religious obligations under Islam. More than 1.5 billion Muslims around the world will mark the month, during which believers abstain from eating, drinking, smoking and having sex from dawn until sunset. Photo by Mohammed Asad