Houthi followers perform the traditional Baraa dance ahead of a demonstration against the Saudi-led air strikes in Yemen's capital Sanaa August 24, 2015. The nothern-based Houthis, a Shi'ite Muslim group, took control of Sanaa last September. Arab countries intervened in the conflict in March to halt a Houthi advance into the south which caused the Saudi-backed government to flee to Riyadh from its refuge in the southern port of Aden. (Photo by Khaled Abdullah/Reuters)

A woman argues as Belarus police block a street during an opposition rally in Minsk, Belarus, Saturday, March 25, 2017. Over the past two months, protests have broken out across the country of 9.5 million, sometimes attracting thousands – initially they were focused on the labor law but have grown to encompass calls for the resignation of President Alexander Lukashenko, whom critics call Europe's last dictator. (Photo by Sergei Grits/AP Photo)

A protester peeks out from behind of a banner as supporters of anti-immigrant activists and nationalists march to protest against the Polish governments decision to accept migrants from Syria and North Africa, in Warsaw, Poland, September12, 2015. EU President Donald Tusk said he would call a special summit on the migration crisis if the bloc's interior ministers do not display “solidarity and unity” at emergency talks on 14 September about the thousands of migrants streaming into Europe. (Photo by Jacek Turczyk/EPA)

A riot policeman fires into the air during clashes with opposition supporters at a rally demanding a referendum to remove President Nicolas Maduro in Caracas, Venezuela, May 11, 2016. (Photo by Carlos Garcia Rawlins/Reuters)

A National Bolivarian Police officer rescues a man who was being attacked by protesters, who then threw rocks at them, during a protest demanding food a few blocks from Miraflores presidential palace in Caracas, Venezuela, Thursday, June 2, 2016. Venezuela is seeing rising frustration with widespread food shortages and triple-digit inflation. (Photo by Fernando Llano/AP Photo)

A 210-kilogram-weight Epinephelussp was showed at China Fisheries & Seafood Expo in Fuzhou, Fujian, China on 24th October, 2014. (Photo by Top Photo/Sipa Press USA)

A visitor looks at a creation by Russian artist Irina Nakhova presented at the Russia's pavilion during the 56th International Art Exhibition (Biennale d'Arte) titled “All the Worlds Futures” on May 5, 2015 in Venice. (Photo by Gabriel Bouys/AFP Photo)