A pro-Russian rebel guards a captured former Ukrainian Army checkpoint outside Vuhlehirsk, Donetsk region, eastern Ukraine, Thursday, February 5, 2015. The rebels have closed in around the town in a strategy they triumphantly refer to as the Debaltseve cauldron. Separatists recently burst through government lines in the rural settlement of Vuhlehirsk. (Photo by Vadim Braydov/AP Photo)

Geese fight during the annual Geese Fight Day in the northern Serbian village of Mokrin, some 160km (100 miles) from Belgrade February 22, 2015. Every year in the last week of February, goose fights are held in the northern Serbian village of Mokrin. Left alone, male geese, or ganders, are unlikely to fight each other, hence why females are brought along for whose affections the ganders then fight until one or the other gives up. (Photo by Marko Djurica/Reuters)

In this March 14, 2015 photo, tourists take pictures from a viewing area at Iguazu Falls in Brazil. From walkways and bridges, viewers can count 270 water falls almost 100 meters (330 feet) high. (Photo by Jorge Saenz/AP Photo)

A massive sand storm cloud is close to enveloping a military camp as it rolls over Al Asad, Iraq, April 27, 2005. (Photo by Cpl. Alicia M. Garcia, U.S. Marine Corps/Reuters/U.S. Department of Defense)

Labourers load a three-wheeled vehicle onto the back of a van at the Mercato market in Addis Ababa October 9, 2015. Addis Ababa's “Mercato” – Italian for “market” – is reputedly the biggest open-air market in Africa, lying in the west of the capital. (Photo by Tiksa Negeri/Reuters)

An inmate with a tattoo of Santa Muerte (The Saint of Death) reacts in the Topo Chico prison, during a media tour, in Monterrey, Mexico, February 17, 2016. The director of a prison in northeast Mexico where 49 people died in a riot this week was accused of murder and detained, along with two others, a state prosecutor said on Saturday. (Photo by Daniel Becerril/Reuters)

A museum employee views “Details of Renaissance Paintings (Sandro Botticelli, Birth of Venus, 1482)” by Andy Warhol at the Victoria and Albert museum in London, Britain, March 2, 2016. The piece forms part of “Botticelli Reimagined”, an exhibition exploring the ways artists have responded to the artistic legacy of the fifteenth century artist Sandro Botticelli, and including over fifty artworks by Botticelli himself. (Photo by Toby Melville/Reuters)

A Chinese bus ushers jump as she pose for a photograph on Tiananmen Square during a plenary session of the National People's Congress held at the Great Hall of the People in Beijing, Wednesday, March 9, 2016. (Photo by Andy Wong/AP Photo)