Demonstrators help a fellow protester during clashes with security forces during an opposition rally in Caracas, Venezuela on April 4, 2017. Protesters clashed with police in Venezuela Tuesday as the opposition mobilized against moves to tighten President Nicolas Maduro' s grip on power. Protesters hurled stones at riot police who fired tear gas as they blocked the demonstrators from advancing through central Caracas, where pro- government activists were also planning to march. (Photo by Carlos Garcia Rawlins/Reuters)

Demonstrators confront riot police during clashes in central Brussels November 6, 2014. Tens of thousands of public and private sector workers, employees and trade union members demonstrated over austerity measures to be taken by the new Belgian government. (Photo by Francois Lenoir/Reuters)

Activists protest against the upcoming visit of Pope Benedict XVI on the eve of his arrival on September 21,2011 in Berlin, Germany. A variety of groups, including the poltically left-wing as well as gay and lesbian rights advocates, partook in the demonstration. The Pope is scheduled to visit Germany from September 22–25. (Photo by Sean Gallup/Getty Images)

Russian Police detain opposition supporters during a “March of Millions” protest rally against Vladimir Putin's return in Moscow, Russia on May 6, 2012. Over 650 people were arrested including opposition leaders. (Photo by Dmitry Schedrin, Rustem Adagamov, Andrey Stenin)

A demonstrator with face painted in the colours of the Palestinian flag protests outside the Israeli Embassy in west London July 26, 2014. Foreign ministers from the United States, Europe and the Middle East called on Saturday for an extension of the 12-hour ceasefire between Israel and Hamas in the Gaza Strip, French Foreign Minister Laurent Fabius said. (Photo by Luke MacGregor/Reuters)

A Russian Sukhoi Su-25 fighter jet takes off during the withdrawal of Russian troops from Syria at Hmeymim airbase, Syria, March 16, 2016. (Photo by Vadim Grishankin/Reuters/Russian Ministry of Defence)

A girl with Russian national flags painted on her cheeks takes part in celebrations marking the first anniversary of Russia's annexation of Crimea, in central Simferopol March 16, 2015. Russia marks one year anniversary of annexation of Ukraine's Crimea peninsula this week. (Photo by Maxim Shemetov/Reuters)

A destroyed T-72 tank, which presumably came from Russia, is seen on a battlefield near separatist-controlled Starobesheve, eastern Ukraine, October 2, 2014. The burnt-out remains of dozens of tanks and armoured vehicles in fields near the small village of Horbatenko bear witness to the ferocity of a battle that turned the tide of the conflict in eastern Ukraine. Among the debris, Reuters found the blackened carcasses of what military experts have since identified as two Russian army tanks, supporting statements by Kiev and the West that the rebels were backed by troops and equipment sent by Moscow. (Photo by Maria Tsvetkova/Reuters)