An armed man herds his cattle close to the village of Nimini in northern South Sudan, February 8, 2017. In the chaos of South Sudan's civil war, it took three years for Nyagonga Machul to find her lost children. Machul had traveled from her village to the capital when President Salva Kiir, an ethnic Dinka, fired his deputy Riek Machar, a Nuer, in 2013. (Photo by Siegfried Modola/Reuters)

Max Niedermaier of Germany collides with uncontrolled motorcycle of Niclas Svensson of Sweden during Astana Expo FIM Ice Speedway Gladiators World Championship at the Medeo rink in Almaty, Kazakhstan, February 18, 2017. (Photo by Shamil Zhumatov/Reuters)

Haitians dressed in costumes dance during the Haitian National Carnival in Jacmel, Haiti, 19 February 2017. Locals and foreigners gathered to enjoy the colorful carnival in which parades are full of art, music and dance. (Photo by Bahare Khodabande/EPA)

Zahra Lari runs in a scene shot for the Nike Middle East ad campaign filmed in Dubai, UAE, February 10, 2017. An online commercial released by Nike (NKE.N) this week that showed Arab women fencing, boxing and spinning on ice-skates has stirred controversy over its attempt to smash stereotypes about women leading home-bound lives in the conservative region. (Photo by Reuters/Nike)

Mexican collector Pablo Perez, holds up a Star Wars R2-D2 toy while he displays a toy collection of Star Wars characters and items at his home in Monterrey, Mexico December 12, 2015. Perez has collected more than 3,000 toys and items from the Star Wars movie series over 10 years, local media reported. (Photo by Daniel Becerril/Reuters)

A truck lays overturned onto a car following strong winds at a Kurnell industrial park after a rare tornado hit the Sydney suburb December 16, 2015. The tornado hit Sydney on Wednesday with destructive winds above 200 km an hour (125 mph) and cricket ball-sized hail, bringing down trees and power lines, tearing off roofs, overturning vehicles and causing flash flooding. (Photo by Jason Reed/Reuters)

A seized weapon is destroyed by the authorities of the General Directive for the Control of Weapons and Munitions, (DIGECAM), in Guatemala City, December 17, 2015. Ninety-one seized weapons belonging to different criminal gangs will be destroyed by the DIGECAM authorities to follow up on a court order, according to the DIGECAM authorities. (Photo by Jorge Dan Lopez/Reuters)

A Thai mahout and his elephant, both dressed as Santa Claus pass in font of a large photograph of Thai King Bhumibol Adulyadej following a Christmas event at a school in the world heritage city of Ayutthaya, north of Bangkok, Thailand, 24 December 2015. The annual event is held to celebrate the Christmas season in the overwhelmingly Buddhist kingdom. (Photo by Diego Azubel/EPA)