A neighborhood watch volunteer stands guard on her street on February 9, 2017 in Peronia, Guatemala. Residents of Peronia, south of Guatemala City organized block by block to secure their community after ten of their neighbors in January were killed, they say, for refusing to pay extortion money to gangs. Armed with machetes and sticks, residents take turns each night, baring strangers' entry into their neighborhoods. Violence and poverty continue to drive emigration from Central America to the United States, even as the Trump administration moves to tighten border security. (Photo by John Moore/Getty Images)

A man cries as he carries his daughter while walking from an Islamic State-controlled part of Mosul towards Iraqi special forces soldiers during a battle in Mosul, Iraq March 4, 2017. Reuters Photographer Goran Tomasevic: “Both screaming in terror, a father and the young daughter he cradled in his arm fled through the rubble-strewn streets of Wadi Hajar, transformed in a flash into a battleground between Islamic State fighters and Iraqi special forces. They and their neighbours – some wearing rubber sandals, some barefoot – were running from an IS counter-attack in this part of Mosul, dodging gunfire as the militants closed in”. (Photo by Goran Tomasevic/Reuters)

An aerial view shows people touring between the large-scale ice sculptures at the 18th Harbin Ice and Snow World during its trial run opening to public in Harbin city, Heilongjiang province, China, 21 December 2016. Some 180,000 cubic meters of ice and 150,000 cubic meters of snow were used to build the 800,000-square-meter ice wonderland. The 33rd Harbin International Ice and Snow Festival will kick off on 05 January 2017 that will last about three months. (Photo by Tian Weitao/EPA)

Medics carry a wounded person at the scene after an attack at a popular nightclub in Istanbul, early Sunday, January 1, 2017. Istanbul Governor Vasip Sahin said that an armed assailant has opened fire at a nightclub in Istanbul during New Year's celebrations. Turkish authorities have banned distribution of images relating to the Istanbul attack within Turkey. (Photo by IHA via AP Photo)

An Iraqi special forces Counter Terrorism Service (CTS) member screams during a battle against Islamic State group jihadists (IS) in Mosul's al-Rifaq neighbourhood on January 8, 2017, as an ongoing military operation against the militants continues. Elite Iraqi forces battling the Islamic State group in eastern Mosul reached the Tigris River that splits the city in two for the first time, a spokesman said. (Photo by Dimitar Dilkoff/AFP Photo)

A penguin swims in its enclosure during a photocall to promote London Zoo's annual stock take of animals on January 4, 2012 in London, England. The zoo's stocktake takes place annually, and gives keepers a chance to check on the numbers of every one of the animals from stick insects and frogs to tigers and camels. (Photo by Dan Kitwood/Getty Images)

In this January 11, 2017 photo, Erika Martins uses black electrical tape to create a customer's bikini, in order to attain crisp tan lines, on her rooftop Erika Bronze salon in the suburb of Realengo in Rio de Janeiro, Brazil. Martins wears a microphone connected to an open speaker system in order to direct her assistants to clients who need more tanning lotion or a sprinkling of water on their skin. (Photo by Renata Brito/AP Photo)

Passengers wait for a train to depart from the Hankou Railway Station in Wuhan, central China's Hubei province, Friday January 13, 2017. Officials expect that Chinese travelers will make almost 3 billion trips during the holiday travel rush that starts runs through Feb. 21. These trips include intercity flights, trains and local bus rides to villages for China's 1.4 billion people. (Photo by Chinatopix via AP Photo)