A makeshift cart with containers is seen at a suspected drug tunnel under construction during a media tour by Mexican Army in Tijuana April 7, 2015. Mexican soldiers foiled the construction of a suspected drug tunnel underneath a house near the U.S. border, arresting nine people and impounding a truck used to clear debris, the Army said on Tuesday. Wired with lights, the tunnel was being built next to the Tijuana border crossing, south of San Diego, California, and near a Mexican air force installation as well as a regional federal police facility. (Photo by Reuters/Stringer)

Pupils of the Dao ethnic tribe return 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)

Afghan women and a boy make their way in Kabul, Afghanistan, Sunday, November 15, 2015. (Photo by Rahmat Gul/AP Photo)

Claudionor Jose de Deus, wearing a Santa Claus costume, arrives at Santa Rosa community to distribute presents to children, on the shores of the Amazon River in rural Manaus, Brazil, December 19, 2015. Jose de Deus is part of a volunteer group that distributes toys to children from poor neighborhoods and riverside communities that are distant from the city. (Photo by Bruno Kelly/Reuters)

“Kilauea Rules”. The most extreme place we put ours kayakers to paddle till now. Photo location: Big Island, Hawaii. (Photo and caption by Alexandre Socci/National Geographic Photo Contest)

Participants take part in a high-heel race at a Gay Pride party in the central neighborhood of Chueca in Madrid on July 3, 2014. (Photo by Gerard Julien/AFP Photo)

Women wearing sunglasses pose for a group photo at a park in Beijing in 1980. (Photo by Reuters/China Daily)

Rescue workers stand near dead bodies washed ashore in Ton Sai Bay in Thailand's Phi Phi island in this December 28, 2004 file photo. On December 26, 2004, a magnitude 9.15 quake off the coast of Indonesia's Aceh province triggered an Indian Ocean tsunami that killed around 226,000 people in Indonesia, Sri Lanka, India, Thailand and nine other countries. (Photo by Luis Enrique Ascui/Reuters)