A protester clashes with a police officer in Athens' central Syntagma (Constitution) Square in this June 15, 2011 file photo. Greece triggered the regional financial crisis in 2009 when a far higher budget deficit than previously calculated emerged. The collapse of talks with creditors in Paris last November set off a month-long sequence of events leading to elections this week and proving Greece is still the region's weak link. The vote is expected to be won by Syriza, a far-left party opposed to the bailout, worrying investors and creditors alike. (Photo by Yannis Behrakis/Reuters)

A woman reacts while walking among the ruins of damaged buildings following heavy fighting between government troops and Kurdish fighters, on March 2, 2016 in the southeastern Turkey Kurdish town of Cizre, near the border with Syria and Iraq. Thousands in Turkey's Kurdish-majority town of Cizre started returning to their homes today after authorities partially lifted a curfew in place since December for a controversial military operation to root out separatist rebels. (Photo by Yasin Akgül/AFP Photo)

A police officer gives instructions to migrants rushing to board a train that would take them towards Serbia, at the railway station in the southern Macedonian town of Gevgelija, Wednesday, August 20, 2015. Macedonian police stepped up the security at the border with Greece apparently trying to stem recent surge of migrants who are coming from Greece. (Photo by Darko Vojinovic/AP Photo)

A woman surveys the damage after the earthquake on March 17, 2011 in Kensennuma, Japan. (Photo by Chris McGrath/Getty Images)

Ukrainian state emblem is seen on a gun's holster as soldiers guard naval base in the village of Novoozernoye, some 91 km west of Crimean capital Simferopol, Ukraine, on Monday, March 3, 2014. Ukraine says Russian forces controlling the strategic region of Crimea are demanding that the crew of two Ukrainian warships in Sevastopol's harbor must surrender. (Photo by Ivan Sekretarev/AP Photo)

An Afghan girl carries water on her back as she climbs a hill in Kabul, Afghanistan February 20, 2017. A growing population is straining water supplies in Afghanistan's capital, forcing those who can afford it to dig unregulated wells ever deeper to tap a falling water table. Finding water in arid Afghanistan is virtually always a challenge, but a drop in the groundwater level in Kabul caused by overuse and drought is making it even more difficult for residents, especially the poor. (Photo by Omar Sobhani/Reuters)

A passenger (C) climbs through the window of an overcrowded bus as limited public transportation operates in the city during the ongoing fuel crisis in Kathmandu, Nepal October 9, 2015. Nepal is considering air-lifting fuel, possibly from Bangladesh, as supply routes from India stay blocked by protesters opposing its new constitution, a short-term solution ahead of a key festival even as the government talks to China for help. (Photo by Navesh Chitrakar/Reuters)