A couple sunbath on the beach in Ostrowo, northern Poland, July 20, 2015. Picture taken July 20, 2015. (Photo by Kacper Pempel/Reuters)

A massive sand storm cloud is close to enveloping a military camp as it rolls over Al Asad, Iraq, April 27, 2005. (Photo by Cpl. Alicia M. Garcia, U.S. Marine Corps/Reuters/U.S. Department of Defense)

A train attendant helps a passenger to adjust her seat at the business class carriage on a CRH 380A bullet train Thursday, June 16, 2011. (Photo by Reuters/China Daily)

A dog walker on Longsands beach before sunrise in Tynemouth, UK on April 1, 2016. (Photo by Owen Humphreys/PA Wire)

Children react as they celebrate Guy Fawkes day in Soweto, South Africa, on November 5, 2014. (Photo by Siphiwe Sibeko/Reuters)

A man runs away during a police round up of suspected drug addicts in Kabul, Afghanistan December 27, 2015. Afghan officials have opened a new drug treatment centre in an abandoned NATO military base in Kabul, in the latest attempt to stamp out the country's massive problem of drug abuse. Camp Phoenix, a former training camp on the edges of Kabul set up by the U.S. army in 2003, will take in around 1,000 homeless drug addicts who will receive food, medical attention and treatment, said Public Health Minister Ferozuddin Feroz. (Photo by Ahmad Masood/Reuters)

People look at huge waves crashing on the San Esteban de Pravia seafront, northern Spanish region of Asturias February 8, 2016. (Photo by Eloy Alonso/Reuters)

This bat gives a cheeky smile as he gobbles down his food at Singapore Zoo, on September 10, 2013. (Photo by Benny Iskander/HotSpot Media)