A health worker checks a traveler's body temperature in a bus as precautionary measures against the spread of COVID-19 at the southern entrance of Sanaa, Yemen, May 9, 2020. (Photo by Mohammed Mohammed/Xinhua)

A health worker checks a traveler's body temperature as precautionary measures against the spread of COVID-19 at the southern entrance of Sanaa, Yemen, May 9, 2020. (Photo by Mohammed Mohammed/Xinhua)

Health workers check travelers' body temperature as precautionary measures against the spread of COVID-19 at the southern entrance of Sanaa, Yemen, May 9, 2020. (Photo by Mohammed Mohammed/Xinhua)

Health workers check travelers' body temperature as precautionary measures against the spread of COVID-19 at the southern entrance of Sanaa, Yemen, May 9, 2020. (Photo by Mohammed Mohammed/Xinhua)