Bjorn, aged 5, smiles as he poses with a Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain March 23, 2016. The exhibition opens to the public on March 24 and runs until September 11. (Photo by Dylan Martinez/Reuters)

South Sudanese wrestlers take part in a wrestling match for peace in Juba on April 19, 2016. The last wrestling match for peace was held in Juba the day before civil war broke out in December 2013. (Photo by Carl de Souza/AFP Photo)

Villagers look on as Mount Sinabung volcano spews thick volcanic ash, as seen from Beganding village in Karo, North Sumatra province, on May 19, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity, it erupted once more in 2013 and has remained highly active since. (Photo by Ivan Damanik/AFP Photo)

Participants of an unauthorized opposition rally gather in Tverskaya street in central Moscow on June 12, 2017. Authorities detained Russian opposition politician Alexei Navalny and hundreds of his supporters on Monday, as they mounted demonstrations across the nation against government corruption. Over 200 were detained in Moscow and Saint Petersburg an hour into the protest, according to an NGO that tracks arrests, with Navalny himself picked up by police in his building as he was headed to the event. (Photo by Vasily Maximov/AFP Photo)

Britain Horse Racing, Royal Ascot, Ascot Racecourse on June 17, 2016. Chelsea pensioners with a racegoer posing between them. (Photo by Toby Melville/Reuters/Livepic)

A soldier beaten by the mob (C) is protected by plain chothes policemen after troops involved in the coup surrendered on the Bosphorus Bridge in Istanbul, Turkey July 16, 2016. (Photo by Murad Sezer/Reuters)

Riot police clash with protesters during a rally to demand a referendum to remove Venezuela's President Nicolas Maduro in Caracas, Venezuela, September 1, 2016. (Photo by Marco Bello/Reuters)

Nepalese women and young girls struggle to drink homemade alcohol poured through a pipe sticking out of the mouth of Swet Bhairab, a god of Power, during the Indra Jatra festival at Basantapur Durbar Square in Kathmandu, Nepal, 17 September 2016. Hundreds of women and young girls gathered to drink alcohol as a blessing from idol of Swet Bhairab which they believes will keep them free from all diseases. The Indra Jatra festival is celebrated to honor Indra, the king of gods and god of rains. The festival also marks the end of the monsoon. (Photo by Narendra Shrestha/EPA)