A fighter of Libyan forces allied with the U.N.-backed government runs for cover during a battle with Islamic State fighters in Sirte, Libya, July 31, 2016. (Photo by Goran Tomasevic/Reuters)

Penitent Jerry Mazon, 9, wears his “Morions” mask while playing with his baby brother during Holy Week celebrations in Mogpog, Marinduque in central Philippines March 22, 2016. (Photo by Erik De Castro/Reuters)

A man climbs up a wooden pole to get a prize during celebration of Maslenitsa, or Pancake Week, a pagan holiday marking the end of winter, near Rumyantsevo, Moscow region, Russia, February 26, 2017. (Photo by Sergei Karpukhin/Reuters)

A man holds his umbrella during snowfall on the Areopagitou pedestrian street beneath the Acropolis hill during snowfall in Athens, Greece, January 10, 2017. (Photo by Alkis Konstantinidis/Reuters)

An employee operates a machine while attaching a lock to a silver chain at the jewelry department of the Krastsvetmet non-ferrous metals plant, one of the world's largest producers in the precious metals industry, in the Siberian city of Krasnoyarsk, Russia, December 14, 2016. (Photo by Ilya Naymushin/Reuters)

People look at damaged trees after a tornado hit Funing on Thursday, in Yancheng, Jiangsu province, China June 24, 2016. (Photo by Aly Song/Reuters)

A girl walks past campaign posters for long-time President Yoweri Museveni, as well as for local members of Parliament, on a street in Kampala, Uganda Wednesday, February 17, 2016. On the eve of presidential elections, a heavy police and military presence could be seen in the capital Kampala. (Photo by Ben Curtis/AP Photo)

Turkana boys play with rifles in a village inside the Turkana region of the Ilemi Triangle, northwest Kenya December 21, 2014. The Ilemi Triangle is a disputed region in East Africa, claimed by South Sudan and Kenya, bordering also Ethiopia. The dispute arose from unclear wording of a 1914 treaty which tried to allow free movement of the Turkana people, nomadic herders who had traditionally grazed the area. (Photo by Goran Tomasevic/Reuters)