A gold prospector is detained by agents of Brazil’s environmental agency on the Uraricoera River during an operation against illegal gold mining on indigenous land, in the heart of the Amazon rainforest, in Roraima state, Brazil April 15, 2016. At over 9.5 million hectares, the Yanomami territory is twice the size of Switzerland and home to around 27,000 indians. The land has legally belonged to the Yanomami since 1992, but illegal miners continue to plague the area, sawing down trees and poisoning rivers with mercury in their lust for gold. (Photo by Bruno Kelly/Reuters)

Anti-government protesters react on the grounds of the Mezhyhirya residence of Ukraine's President Viktor Yanukovich in the village Novi Petrivtsi, outside Kiev February 22, 2014. (Photo by Konstantin Chernichkin/Reuters)

Children surround a man, left, that fell down while walking on a street suspected of having contracted the Ebola virus in the city of Monrovia, Liberia, Tuesday, August 19, 2014. The World Health Organization says the outbreak has killed more than 1,200 people, while authorities struggle to contain its spread and treat the sick. (Photo by Abbas Dulleh/AP Photo)

Latefat Alao, 56, a ethnic Yoruba Muslim woman, waits for customers in front of her in Beere market in Ibadan, southwest Nigeria, January 29, 2015. Much of the grain and wheat traders like Alao sell comes from the north and Boko Haram's campaign has negatively affected farmers and food markets. Reuters photographer Akintunde Akinleye photographed Nigerians and asked them about their views on the elections as well as their hopes and concerns for the country. (Photo by Akintunde Akinleye/Reuters)

“DC3 Wreck”. A capture of a US military DC3 plane wreck at the southern black beach in Iceland. Photo location: Iceland. (Photo and caption by Naian Feng/National Geographic Photo Contest)

First graders of a cadet's lyceum attend a ceremony to mark the start of the new school year in Kiev, Ukraine, September 1, 2015. September 1 marks the start of a new academic year for students in Ukraine.(Photo by Valentyn Ogirenko/Reuters)

Bison along the Bitterroot Valley's Eastside Highway north of Stevensville, Montana, are covered in snow following a blizzard on November 23, 2010. (Photo by Perry Backus/The Missoulian)

A picture released by the North Korean Central News Agency (KCNA) shows Kim Jong-un convening an urgent operation meeting at 0:30 am on March 29, 2013 at an undisclosed location, in which he ordered strategic rocket forces to be on standby to strike US and South Korean targets at any time. (Photo by KCNA via EPA)