Dancers take part in the Karneval der Kulturen (Carnival of Cultures) street parade of ethnic minorities in Berlin, Germany, May 15, 2016. (Photo by Hannibal Hanschke/Reuters)

Children wave Vietnamese and American flags while waiting for arrival of U.S. President Barack Obama (not pictured) before a welcoming ceremony at the Presidential Palace in Hanoi, Vietnam May 23, 2016. (Photo by Reuters/Kham)

Kaitlin, 28, from the United States is suspended from hooks pierced through her skin by the professional body artist Dino Helvida in Zagreb, Croatia June 7, 2016. (Photo by Antonio Bronic/Reuters)

Somali government soldiers hold their positions during gunfire after a suicide bomb attack outside Nasahablood hotel in Somalia's capital Mogadishu, June 25, 2016. Somalia's al Shabaab Islamist group launched a suicide bomb attack on a hotel in the center of Mogadishu on Saturday before fighters stormed inside, police and the militant group said. Police said at least 15 people had died, including guards at the site, civilians and militants. Others were wounded. (Photo by Feisal Omar/Reuters)

A U.S. army soldier exercises in front of a M270A1 multiple launch rocket system as they prepare for a live-fire training exercise of the 6-37th Field Artillery Regiment at a training area near the demilitarized zone separating the two Koreas, in Cheorwon, South Korea, March 9, 2016. (Photo by Kim Hong-Ji/Reuters)

A pilot looks up from a U.S. F-22 Raptor fighter as it prepares to refuel in mid-air with a KC-135 refuelling plane over European airspace during a flight to Britain from Mihail Kogalniceanu air base in Romania April 25, 2016. (Photo by Toby Melville/Reuters)

A migrant holds a placard which reads “No Forced Deportations” as he rides his bicycle at the makeshift camp called “The New Jungle” in Calais, France, September 18, 2015. Around 3,500 migrants and refugees are camped in Calais, fleeing war and poverty in the Middle East, Africa and Asia and now living in the jungle. Most of them are hoping to make the crossing to England. (Photo by Regis Duvignau/Reuters)

A pupil of the Dao ethnic tribe returns home from school along a hillside path at Suoi Thau village in Hoang Su Phi district of Vietnam's northern province of Ha Giang, located at the border with China, September 18, 2015. (Photo by Reuters/Kham)