A youth dives into a crater filled with water in Aleppo's al-Shaar district, in this July 10, 2014 file photo. (Photo by Hosam Katan/Reuters)

Pro-Russian rebels stand near a monument during a ceremony to honour the World War Two defenders of Donetsk from Nazi forces, in Donetsk, in this September 8, 2014 file photo. (Photo by Marko Djurica/Reuters)

Mount Sinabung volcano erupts, as seen from Tiga Pancur village, Karo Regency in Indonesia's North Sumatra province, in this October 8, 2014 file photo. (Photo by Y. T. Haryono/Reuters)

The Chinese community in Glasgow celebrate Chinese New Year in Glasgow City Chamber on January 29, 2017. The Chinese Lunar New Year also known as the Spring Festival, which is based on the Lunisolar Chinese calendar, is celebrated from the first day of the first month of the lunar year and ends with Lantern Festival on the fifteenth day. (Photo by Jeff J. Mitchell/Getty Images)

The battle by Jose Garcia, US. Category: bird behaviour. A great white heron (Ardea herodias occidentalis) fighting a green snake in the Florida Everglades. The fight lasted for nearly 20 minutes with the heron having to release its prey. (Photo by Jose Garcia/2017 Bird Photographer of the Year Awards)

An internally displaced woman collects water from a pond to construct a mud-house at the Aboushok camp in El Fasher, North Darfur, Sudan, November 17, 2015. The conflict in Sudan's Darfur region that erupted 12 years ago shows no sign of ending. But it hasn't stopped displaced youngsters, some of whom have spent their entire lives in refugee camps, from dreaming big. Twelve children aged 12 explain their hopes and dreams for the future; ambitions include becoming a doctor, an engineer and a teacher. (Photo by Mohamed Nureldin Abdallah/Reuters)

Members of a Chinese opera take a selfie before a performance at a shopping mall ahead of the Chinese Lunar New Year celebrations in Bangkok, Thailand, February 4, 2016. (Photo by Athit Perawongmetha/Reuters)

A man wears a costume during a parade to celebrate the Chinese Lunar New Year, which welcomes the Year of the Monkey, in Madrid, Spain, February 13, 2016. (Photo by Andrea Comas/Reuters)