A military instructor helps a boy to shoot a rifle with blanks at a weapon exhibition during a military show in St.Petersburg, Russia, Sunday, January 17, 2016. (Photo by Dmitry Lovetsky/AP Photo)

Magbola Alhadi, 20, and her three children pose for a portrait in Jamam refugee camp in Maban County, South Sudan on August 11th, 2012. Magboola and her family weathered aerial bombing raids for several months, but decided it was time to leave their village of Bofe the night that soldiers arrived and opened fire. With her three children, she travelled for 12 days from Bofe to the town of El Fudj, on the South Sudanese border. The most important thing that Magboola was able to bring with her is the saucepan she holds in this photograph. It wasn't the largest pot that she had in Bofe, but it was small enough she could travel with it, yet big enough to cook sorghum for herself and her three daughters (from left: Aduna Omar, 6, Halima Omar, 4, and Arfa Omar, 2) during their journey. (Photo by Brian Sokol/Panos Pictures)

A Houthi follower with fake blood on his clothes lies on the ground to represent a victim as others perform a war dance during a ceremony marking the first anniversary of the Houthi movement's takeover of Yemen's capital Sanaa September 21, 2015. (Photo by Khaled Abdullah/Reuters)

Soldiers of China's People's Liberation Army (PLA) jump as part of their winter training in temperature of negative 26 degrees Celsius at China's border with Russia in Heihe, Heilongjiang province, December 14, 2015. (Photo by Reuters/Stringer)

Paramilitary policemen take part in a training in Chaohu, Anhui province, China December 28, 2015. (Photo by Reuters/China Daily)

A new book published by the UK Natural History Museum showcases some of the most memorable underwater photographs taken over the last few decades in its annual wildlife photographer of the year competition. Here: Giant gathering by Tony Wu. “The first indication that something extraordinary was going on were the blows, huge numbers of them – the exhalations of huge numbers of whales. Entering the water, the photographer witnessed an extraordinary scene”. (Photo by Tony Wu/Unforgettable Underwater Photography/NHM)

A tribal fighter loyal to Yemen's government stands in Al Khurais village of Nihm district east of the capital Sanaa January 11, 2016. (Photo by Ali Owidha/Reuters)

People walk past a New Year fir tree made of toys at a park in Krasnoyarsk, Siberia, Russia January 2, 2017. (Photo by Ilya Naymushin/Reuters)