Russian police detain a protester at a demonstration against President Vladimir Putin in St.Petersburg, Russia, Saturday, May 5, 2018. (Photo by Dmitri Lovetsky/AP Photo)

Undated UK Ministry of Defence handout photo of an RAF Tornado GR4 which has been painted in Gulf War “desert pink” paint scheme to honour the aircraft type's almost continuous operational service since the Royal Air Force helped liberate Kuwait from Saddam Hussein's forces, taken by SAC Rose Buchanan, which has been shortlisted for the general public to pick their favourite RAF Image of the Year. (Photo by SAC Rose Buchanan/MoD Crown Copyright/PA Wire)

Girls hold hands as they help each other wade through a flooded street after the passing of Hurricane Matthew in Les Cayes, Haiti, Thursday, October 6, 2016. Two days after the storm rampaged across the country's remote southwestern peninsula, authorities and aid workers still lack a clear picture of what they fear is the country's biggest disaster in years. (Photo by Dieu Nalio Chery/AP Photo)

Iraqi forces launch a rocket in Mosul's eastern Al-Intisar neighbourhood on December 30, 2016, during an ongoing military operation against Islamic State (IS) group jihadists. Iraqi forces advanced on December 29 after declaring a new phase in their offensive on eastern Mosul, stepping up efforts to reclaim the Islamic State group's last major stronghold in the country. (Photo by Ahmad Al-Rubaye/AFP Photo)

Mohammad, a 13-year-old fighter from the “Free Syrian Army”, plays with a cat in Aleppo's Bustan al-Basha district, Syria October 28, 2013. Mohammad joined the Free Syrian Army after his father died during clashes with the Syrian regime. The gun he is using was his father's. (Photo by Molhem Barakat/Reuters)

In this May 8, 2015 photo, sisters Zoraida Infante, left, and Graciela Trujillo pray on Fishermen's Beach before therapeutic swimming in the Pacific Ocean in Lima, Peru. Under overcast skies, the bathers practice thalassotherapy, which derives from the Greek “thalasso”, for “sea”, and draws on the ocean's healing properties. (Photo by Rodrigo Abd/AP Photo)

A silkmoth that has hatched out of its cocoon is seen at the Campoverde cooperative, Castelfranco Veneto, Italy June 4, 2015. Despite having wings, the adult moth cannot fly. Clusters of silkworms munch on piles of locally-grown mulberry leaves in a white marquee in Italy's northern Veneto region. They are nourishing hopes of a revival of Italy's 1,000 year-old silk industry. (Photo by Alessandro Bianchi/Reuters)

In this photo taken Thursday, August 13, 2015, a man walks past the charred remains of new cars at a parking lot near the site of an explosion at a warehouse in northeastern China's Tianjin municipality. Rescuers have pulled a survivor from an industrial zone about 32 hours after it was devastated by huge blasts in China's Tianjin port. Meanwhile, authorities are moving gingerly forward in dealing with a fire still smoldering amid potentially dangerous chemicals. (Photo by Ng Han Guan/AP Photo)