North Korean children wave to people on a Chinese tourist boat on the banks of Yalu River near the Chongsong county of North Korea, opposite the Chinese border city of Dandong, May 8, 2011. (Photo by Jacky Chen/Reuters)

A riot policeman uses a baton to hit a rioting University of Nairobi student in Kenya's capital Nairobi, in this May 20, 2014 file photo. (Photo by Noor Khamis/Reuters)

An undated archive picture shows a dog pulling a Belgian machine gun at an unknown location in northern France. A Viscount in the Armoured Cavalry Branch of the French Army left behind a collection of hundreds of glass plates taken during World War One (WWI) that have never before been published. The images, by an unknown photographer, show the daily life of soldiers in the trenches, destruction of towns and military leaders. The year 2014 marks the 100th anniversary of the start of WWI. (Photo by Collection Odette Carrez/Reuters)

Robert The Bruce's army from The Clanranald Trust during a rehearsal for the Battle of Bannockburn re-enactment performance which will be staged at the Bannockburn Live Event in Bannockburn, the 700th anniversary of the battle, on June 27, 2014. (Photo by Andrew Milligan/PA Wire)

A protester throws a stone towards a burning police bus in front of him, during clashes with police, in central Kiev, Ukraine, Sunday, January 19, 2014. Hundreds of protesters on Sunday clashed with riot police in the center of the Ukrainian capital, after the passage of harsh anti-protest legislation last week seen as part of attempts to quash anti-government demonstrations. The violent scenes further escalated this ex-Soviet republic's political crisis and showed a rift among opposition leaders, one of whom fought bravely to stop the violence, while others condemned the events from afar. (Photo by Evgeny Feldman/AP Photo)

A lightning strikes St Peter's dome at the Vatican on February 11, 2013. Pope Benedict XVI announced today he will resign as leader of the world's 1.1 billion Catholics on February 28 because his age prevented him from carrying out his duties – an unprecedented move in the modern history of the Catholic Church. (Photo by Filippo Monteforte/AFP Photo)

Residents walk past electoral posters in Port-au-Prince, Haiti, January 28, 2017. (Photo by Andres Martinez Casares/Reuters)

Dancers wearing traditional attires take part in the 7th Annual Ingoma Dance Competition organised by The Natal Playhouse theatre in Durban on March 21, 2017. The Ingoma Dance is considered one of the most purist forms of traditional Zulu dance. (Photo by Rajesh Jantilal/AFP Photo)