People look at a man, who residents said was killed by al Qaeda militants, hanging on a bridge in Yemen's southeastern city of Mukalla June 17, 2015. Al Qaeda militants in Yemen killed two alleged Saudi spies, residents said, accusing them of planting tracking devices which enabled the assassination of the group's leader in a suspected U.S. drone strike. (Photo by Reuters/Stringer)

A woman walks past graffiti in Beirut, Lebanon, Wednesday, May 4, 2016. Graffiti artists have been trying to re-engage disillusioned youth in a debate about the country's latest wave of political turmoil. (Photo by Hassan Ammar/AP Photo)

A policeman kick in the door of a residence next to the Black Panther headquarters in New Orleans as they moved in following a shootout, September 15, 1970. Other heavily armed policemen stand at ready. (Photo by Jack Thornell/AP Photo)

A Flemish demonstrator, one of thousands who gathered for a march through Brussels to protest against what the Flemings call their subjucation by the French-speaking Walloons, draws back as he is jeered by a crowd of Walloons on the pavement in a Brussels Street, on October 14, 1962. The Flemish demonstrators clashed with Walloon counter demonstrators as riot police sought to maintain order. The Flemings claim that although they form 60% of the population in Belgium, they are inadequately represented in the government, and they say, the Walloons get most of the top jobs in the armed forces and the diplomatic service. (Photo by AP Photo)

A woman carries water during during a visit by a European Union delegation, at an IDP camp in Azaza, east of Ad Damazin, capital of Blue Nile state, October 21, 2015. The camp houses people displaced by war between the Sudan People's Liberation Movement-North (SPLM-N) rebels and the Sudanese government. (Photo by Mohamed Nureldin Abdallah/Reuters)

Hemispheric color differences on Saturn's moon Rhea are apparent in this false-color view from NASA's Cassini spacecraft in this March 2, 2010 file photo. (Photo by Reuters/NASA/JPL/SSI)

Rungis is a commune in the southern suburbs of Paris, France. It is best known as the location of the large wholesale food market serving the Paris metropolitan area and beyond, the Marché d'Intérêt National de Rungis, said to be the largest food market in the world. The name Rungis was recorded for the first time in a royal charter of 1124 as Rungi Villa. Here: swordfish are sold at the fish pavilion in Rungis International food market as buyers prepare for the Christmas holiday season in Rungis, south of Paris, December 11, 2015. (Photo by Philippe Wojazer/Reuters)

Tsunami, an eleven year old female Sumatran Orangutan eats a fruit platter during her birthday celebration at the National Zoo Ape Center in Kuala Lumpur, Malaysia, Thursday, December 31, 2015. (Photo by Manan Vatsyayana/AFP Photo)