Visitors and a dog stand on the new “Skywalk” viewing platform on the Sonnenstein mountain in the Eichsfeld region near Bad Lauterberg im Harz, central Germany, on May 22, 2017. (Photo by Martin Schutt/AFP Photo/DPA)

Demonstrators clash with members of the Bolivarian National Police as protests continue in Caracas, Venezuela, 20 April 2017. The Bolivarian National Guard, using tear gas, tried to disperse protests against the government of Venezuelan President Nicolas Maduro. (Photo by Miguel Gutierrez/EPA)

A girl watches as Saen Dao, an eight-year-old female asian elephant, and her mahout perform underwater during a show at the Khao Kheow Open Zoo in Chonburi south of Bangkok on June 1, 2017. (Photo by Roberto Schmidt/AFP Photo)

Italian Air Force's aerobatic demonstration team, the Frecce Tricolori leave colourful vapour trails as they fly over the Altare della Patria monument on Republic Day (Festa della Repubblica) in Rome, Italy, 02 Jun 2017. The anniversary marks the founding of the Italian Republic in 1946. (Photo by Massimo Percossi/EPA)

A masked Burundian protester faces soldiers in front of a burning barricade during an anti-government demonstration against President Pierre Nkurunziza's bid for a third term in the capital Bujumbura, Burundi, 25 May 2015. Street protests continued on 25 May as the United Nations Secretary-General Ban Ki-moon condemned the killing of the leader of the oppsition party Union for Peace and Development (UPD) Zedi Feruzi who opposed Nkurunziza's bid. (Photo by Dai Kurokawa/EPA)

Revellers pose during the 24th Street Parade dance music event in Zurich, August 29, 2015. (Photo by Arnd Wiegmann/Reuters)

A clothing shop displays its merchandise in the rebel-controlled city of Idlib, Syria November 7, 2015. (Photo by Ammar Abdullah/Reuters)

Revellers take part in an annual block party known as “Cordao de Prata Preta”, one of the many carnival parties to take place in the neighbourhoods of Rio de Janeiro, February 6, 2016. (Photo by Pilar Olivares/Reuters)