An anti-government protester wearing a Guy Fawkes mask stands with a shield near flames from molotov cocktails thrown at a water cannon by anti-government protesters during riots in Caracas in this April 20, 2014 file photo. (Photo by Jorge Silva/Reuters)

Swiss police officers stand beside of mock gates of the NEAT Gotthard Base Tunnel inside the event hall for the upcoming opening ceremony near the town of Erstfeld, Switzerland May 31, 2016. The celebrations of the opening of the Gotthard Base Tunnel will start on June 1, 2016. With a length of 57 km (35 miles) crossing the Alps, the Gotthard Base tunnel is the world's longest train tunnel. (Photo by Arnd Wiegmann/Reuters)

A hat and boots belonging to a volunteer with the Israeli Antique Authority are seen inside the Cave of the Skulls, an excavation site in the Judean Desert near the Dead Sea, Israel June 1, 2016. A team of volunteers and archaeologists are searching for remains of The Dead Sea Scrolls, one of the oldest known Hebrew texts, in a national bid, initiated by the Israel Antiquities Authority (IAA), to prevent the robbery of such important artefacts and once found to hand them over to the state for preservation. (Photo by Ronen Zvulun/Reuters)

A dancer dressed for the annual procession honoring San Pedro, his town's patron saint, runs through the street of San Pedro Sacatepequez near Guatemala City June 29, 2016. (Photo by Saul Martinez/Reuters)

People walk on the installation “The Floating Piers” on Lake Iseo by Bulgarian-born artist Christo Vladimirov Yavachev, known as Christo, at the installation's last weekend near Sulzano, northern Italy, July 2, 2016. (Photo by Wolfgang Rattay/Reuters)

A masked Kashmiri protester shouts freedom slogan near burning tires set up as road blockade by protesters in Srinagar, Indian controlled Kashmir, Tuesday, July 19, 2016. The largest street protests in recent years in the disputed region, that left dozens of people dead and hundreds injured erupted more than a week ago after Indian troops killed a popular young rebel leader. (Photo by Dar Yasin/AP Photo)

A woman uses a tree branch to fight a fire on the road leading to the village of Parada, near Mortagua, northern Portugal, Thursday, August 11 2016. Firefighters in Portugal are battling multiple blazes fed by brush in a hot, dry summer for a sixth straight day. Major fires have also been raging in northwestern Spain and southern France. (Photo by Sergio Azenha/AP Photo)

Pine trees are seen after a forest fire near Sao Pedro do Sul, Portugal August 14, 2016. Deadly wildfires raging for two weeks in Portugal have destroyed a wooded area the size of 100,000 soccer fields, and the small Iberian nation alone accounts for half of all forests burned in the European Union this year. (Photo by Rafael Marchante/Reuters)