Revelers, covered in coloured powder, celebrate, during a Holi Run Festival in Madrid, Spain, Sunday, April 12, 2015. Thousands of revelers took part in the festival that includes a mini marathon. The festivals are fashioned after the Hindu spring festival Holi, which is mainly celebrated in the north and east of India. (Photo by Andres Kudacki/AP Photo)

Afghan firefighters spray water on a U.S. armoured vehicle after a suicide attack on the outskirts of Jalalabad, January 5, 2015. A suicide attacker targeted a U.S. convoy on the outskirts of Jalalabad on Monday but so far no causalities have been reported yet, provincial spokesman Ahmadzia Abdulzai said. (Photo by Reuters/Parwiz)

A demonstrator attends a protest against fare hikes for city buses in Rio de Janeiro January 16, 2015. Amid a marked economic downturn and high inflation, bus fares went up in Sao Paulo, Brazil's largest city, from 3 to 3.50 reais, and in Rio, the former capital, from 3.0 to 3.40 reais. (Photo by Mauro Pimentel/Reuters)

Mohamed Badr al-Din (R) stands in front of his vintage cars along a street where he keeps them, in the al-Shaar neighborhood of Aleppo January 31, 2015. The 66-year-old collector nicknamed Abu Omar inherited the hobby from his father and has a large collection of vintage cars, some of which he says belonged to former Syrian officials and were used in several movies and shows. Before the unrest, Abu Omar planned to open a museum to display his cars, which are guarded from pedestrians by a turkey that he owns. He hopes that the turmoil in the country will end so that he can pursue his hobby and repair his cars, which are heavily damaged from shelling. (Photo by Abdalrhman Ismail/Reuters)

British troops arriving in England on June 6, 1940 after fleeing Flanders received all kinds of fruit and food from women who passed it out to them as they halted in railroad stations. A soldier holds aloft a banana he received from the woman. (Photo by AP Photo)

A policeman controls traffic at 42nd Street and 7th Avenue as New York City remains without electricity caused by a blackout that affected the entire city and most of the eastern part of the nation August 15, 2003 in New York, New York. More than 50 million people were affected by the outage, in Toronto, Detroit, Cleveland and New York City. (Photo by Jose Jimenez/Primera Hora/Getty Images)

“The power of nature”. Magma, ash and gas erupt from Mount Etna in December 2015, rising to a height of several kilometres. Winner: Nature. (Photo by Giuseppe Mario Famiani/SIPA Contest)

Boys pan for gold on a riverside at Iga Barriere, 25 km (15 miles) from Bunia, in the resource-rich Ituri region of eastern Congo February 16, 2009. Ituri is one of many areas of the country to have experienced bitter ethnic conflict between rival tribes in recent years. Massacres have left tens of thousands dead. It is this fighting that led U.S. authorities to take the unprecedented step of naming Congo in section 1502 of the Dodd-Frank financial regulation act, which says U.S.-listed companies that source gold, tungsten, tantalum and tin from Congo or its neighbours must assure the U.S. stock exchange regulator that their business is not helping fund conflict. (Photo by Finbarr O'Reilly/Reuters)