Riot police stand guard behind a fire as refinery workers hold a blockade of the oil depot of Douchy-Les-Mines to protest against the government's proposed labour reforms, on May 25, 2016. Refinery workers stepped up strikes that threaten to paralyse France weeks ahead of the Euro 2016 tournament as the government moved to break their blockades, escalating a three-month tug-of-war over labour reforms. (Photo by François L.O./AFP Photo)

A couple embrace during the start of the San Fermin festival in Pamplona, Spain July 6, 2016. Revelers from around the world kick off the festival with a messy party in the Pamplona town square, one day before the first of eight days of the running of the bulls. (Photo by Vincent West/Reuters)

A wounded protester is attended before being rushed to a vehicle following violence in Independence Square in Kiev February 20, 2014. Ukrainian protesters seized back Kiev's Independence Square in fresh clashes with riot police on Thursday that left several injured and possibly two demonstrators dead. (Photo by Konstantin Chernichkin/Reuters)

David Jackson (C), who voted for Donald Trump, has a discussion with Ryan Graves (L) and Anna Kaminski (R) visiting from Oamaha, Nebraska during a rally against the election of Republican Donald Trump as President of the United States in downtown Indianapolis, Indiana, U.S., November 12, 2016. (Photo by Clay Lomneth/Reuters)

Iranian demonstrators burn an Israeli flag during a rally marking al-Quds (Jerusalem) Day in Tehran July 10, 2015. (Photo by Reuters/Stringer/TIMA)

Revellers celebrate the death of Britain's former prime minister Margaret Thatcher in Brixton, south London April 8, 2013. Margaret Thatcher, the “Iron Lady” who transformed Britain and inspired conservatives around the world by radically rolling back the state during her 11 years in power, died on Monday following a stroke. She was 87. (Photo by Olivia Harris/Reuters)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

A pink elephant balloon, one of the entries in the Canadian Hot Air Balloon Championships, lands in a field in High River September 27, 2013. The event is a qualifier for the World Hot Air Balloon Championships in Sao Paulo in 2014. (Photo by Mike Sturk/Reuters)