A Yemeni grain vendor waits for customers in Sanaa, Yemen, Oct. 16, 2019, the World Food Day. The long-running conflict has caused the world's worst humanitarian crisis. Currently, some 24 million Yemenis, or 80 percent of the population, need humanitarian aid and protection, with some 20 million lacking food security, according to previous UN statistics. (Photo by Mohammed Mohammed/Xinhua)