An army tank fires during a firefight against militants linked to al Qaeda near the southern Yemeni city of Zinjibar May 30, 2012. (Photo by Reuters/Yemen's Defence Ministry)

Sergei Bobkov, 59, paints Siberian cedar nut oil onto a life-size sculpture of Pallas's Cat, also known in Russia as Manul Cat, which he made from Siberian cedar wood shavings using more than 700 thousand pieces over four years, in the village of Kozhany, southwest of the Siberian city of Krasnoyarsk, Russia, April 28, 2017. (Photo by Ilya Naymushin/Reuters)

Max Gold, 20, of NYC, cruises on his skateboard as thousands gather on the National Mall for the March for Science on Saturday, April 22, 2017, in Washington, DC. Activists and scientists descend on the nation's capital to rally for environmental causes and government policies rooted in scientific research as part of the Earth Day and March for Science rallies. (Photo by Jahi Chikwendiu/The Washington Post)

Yakelin Hernandez, 18, poses for a photograph near The Malecon where The Carnival was held, on August 14, 2015. Colorful costumes, dancing, parades and street parties on the Malecon in Havana, Cuba are all part of Havana Carnival 2015 which was held in August. (Photo by Sarah L. Voisin/The Washington Post)

Kieron Connolly’s new book of photographs of more than 100 once-busy and often elegant buildings gives an idea of how the world might look if humankind disappeared. Here: Bodie, Mono County, California. Gold was discovered at Bodie in 1859 (just after the initial California gold rush) and it went from mining camp to boomtown. Its decline began in 1880, when word spread of new boomtowns elsewhere. The Standard Consolidated Mine closed in 1913, and four years later the Bodie Railway was abandoned. By 1940 the population was down to 40. Today, Bodie is maintained in a state of arrested decay as a visitor attraction. (Photo by Alamy Stock Photo)

Throughout the course of the long war in Afghanistan, Coalition troops have relied on thousands of military working dogs to help keep them safe, and make their jobs easier. The dogs are trained to detect explosives, to find illegal drugs, to search for missing comrades, or target enemy combatants. Not only are they active on the front lines, but behind the lines they serve as therapy dogs, service dogs, and loyal companions. They also share the same risks as the ground troops, suffering injuries and sometimes death on the battlefields. Gathered here are images of these dogs and their handlers in Afghanistan and back home, from over the past several years, part of the ongoing series here on Afghanistan.

A sun bear reacts to triple-digit temperatures at the Henry Doorly Zoo in Omaha, Nebraska, where the temperature reached 103 degrees Fahrenheit on July 6, 2012. (Photo by Nati Harnik/Associated Press)

The 100-metre (300-foot), sword-wielding statue of “The Motherland” is seen in the National Museum of the History of the Great Patriotic War in Kiev March 17, 2014. On a blustery day on the banks of the Dnieper, the statue of “The Motherland”, a Soviet hammer and sickle on her shield, towered overhead, a reminder of the common cause Ukrainians and Russians died for side by side in their millions in World War Two and which Russian President Vladimir Putin thinks Ukraine has betrayed by turning to “fascism” and the West. (Photo by Konstantin Grishin/Reuters)