A bunker at aformer Swiss artillery fortress called Heldsberg stands near the town of St. Margareten, Switzerland March 22, 2015. Heldsberg fortress, located on the Swiss-Austrian border near the River Rhine and Lake Constance was built from 1938 to 1940 and remained in military use until 1992. Since 1993 it is open to the public as Fortress Museum Heldsberg. (Photo by Arnd Wiegmann/Reuters)

Palestinian children warm themselves by a fire on a stormy day at Shati (beach) refugee camp in Gaza City January 18, 2016. (Photo by Mohammed Salem/Reuters)

A picture made available on 07 March 2016 shows visitors petting and holding a Fennec fox, native to the Sahara, in the petting room at the Little Zoo Cafe, a business built to capitalize on Thais' love for exotic animals, and food, on the outskirts of Bangkok, Thailand, 05 March 2016. The cafe boasts Fennec foxes, Meerkat, native to parts of Africa, Silver Fox, Raccoon and Chinchillas, along with a menu of Thai food and Cheesecake, among other sweet deserts. Nature is a faraway fantasy in the bustling exhaust-filled cement city of Bangkok, fuelling a demand to own and be close to exotic pets. The trend to be near to a species that was once wild, in a city environment, far from the natural setting, has drawn criticism but continues to grow. (Photo by Barbara Walton/EPA)

Refugee children play with a stuffed toy at a muddy makeshift camp at the Greek-Macedonian border, near the village of Idomeni, Greece March 15, 2016. (Photo by Alexandros Avramidis/Reuters)

An aerial view of the new Panama Canal expansion project on the Atlantic side of the Panama Canal during an organized media tour by Italy's Salini Impregilo, one of the main sub contractors of the Panama Canal Expansion project, in Panama City May 11, 2016. The newly expanded Panama Canal will be inaugurated on June 26, 2016. (Photo by Carlos Jasso/Reuters)

A police officer carries a woman who fainted while gathering to try to buy pasta outside a supermarket in Caracas, Venezuela, June 10, 2016. (Photo by Carlos Garcia Rawlins/Reuters)

A member of the Philippine National Police stands guard as he detains people as part of the “Rid the Streets Of Drinkers and Youth” operation on a main road in Las Pinas city, metro Manila, Philippines June 1, 2016. (Photo by Romeo Ranoco/Reuters)

Iraqi Kurdish refugees wait with children in Cukurca refugee camp in Turkey April 8, 1991. Reuters photographers have chronicled Kurdish refugee crises over the years. In 1991 Srdjan Zivulovic documented refugees in Cukurca who had escaped a military operation by Saddam Hussein's government in Iraq aimed at “Arabising” Kurdish areas in the north. Hundreds of thousands fled into Turkey and Iran. Images shot in recent months show familiar scenes as crowds of people flee Islamic State militants in Syria. There are as many as 30 million Kurds, spread through Turkey, Iraq, Syria and Iran. Most Kurds are Sunni Muslims, but tend to feel more loyalty to their Kurdishness, rather than their religion. (Photo by Srdjan Zivulovic/Reuters)