A man sleeps on a wheelbarrow outside a closed shop at a market during the first day of a ceasefire in Yemen's capital Sanaa April 11, 2016. (Photo by Khaled Abdullah/Reuters)

A boy holds the remains of a mortar shell which hit a residential building in the village of Staromikhailovka, outside the separatist-held city of Donetsk, Ukraine, May 24, 2016. (Photo by Alexander Ermochenko/Reuters)

A man demonstrates outside Republican presidential candidate Donald Trump's news conference at Trump Tower in New York, U.S., May 31, 2016. (Photo by Shannon Stapleton/Reuters)

A worker carries a bag of peeled carrots on her head outside a vegetable market in La Trinidad, Benguet in northern Philippines August 6, 2016. (Photo by Erik De Castro/Reuters)

CHINA: Customers eat at a restaurant as a cooked pig sits on a cart on the street outside in Hong Kong, China, December 12, 2016. (Photo by David Gray/Reuters)

Ukrainian emergency workers spray a plane with water hoses as part of a rescue training exercise at Boryspil International Airport outside Kiev, Ukraine, September 27, 2016. (Photo by Valentyn Ogirenko/Reuters)

A truck carrying gold miners across the Sahara desert to far northern Niger drives outside Agadez, Niger, May 9, 2016. (Photo by Joe Penney/Reuters)

A protestor performs outside the parliament during a demonstration against austerity measures announced by the Spanish government in Madrid, Spain on September 29, 2012. (Photo by Andres Kudacki/Associated Press)