In this picture taken on September 24, 2016, relatives grieve their lost one, an alleged drug user/dealer gunned down by unidentified gunmen in Manila. Philippine President Rodrigo Duterte defended his threat to kill criminals as “perfect” and vowed no let-up in his war on crime, as the death toll surged past 3,700. (Photo by Noel Celis/AFP 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.

Actor Brad Pitt films a scene from “World War Z” in Glasgow City centre on August 18, 2011 in Glasgow, Scotland. The film, which is set in Philadelphia, will be shot in various parts of the city transforming it into ruins to shoot a post apocalyptic zombie film. (Photo by Jeff J Mitchell/Getty Images)

The number of soldiers on both sides of WWII that were killed or went missing is just staggering. Now, the mystery surrounding one RAF pilot and what happened to him and his plane has been solved after 70 years. RAF flight Sergeant Dennis Copping climbed into his Kittyhawk P-40 aircraft in June 1942 to fly the plane to another airbase for repairs. He was never seen or heard from again.

Tajammu Al-Ezza brigade fighters react while firing a Grad shell towards forces of Syria's President Bashar Al-Assad stationed in Salhab village, Hama countryside, May 7, 2015. (Photo by Mohamad Bayoush/Reuters)

Canadian soldiers from the Royal 22nd Regiment take up a position during a non-combative extraction operation in a simulated village as part of Rim of the Pacific (RIMPAC) 2016 exercise held at Camp Pendleton, California United States, July 11, 2016. (Photo by Mike Blake/Reuters)

A ship being used for the filming of World War Z sets sail from Falmouth Harbour on August 4, 2011 in Falmouth, United Kingdom. The Cornish coastal town is currently being used to film the zombie film that stars Brad Pitt. (Photo by Matt Cardy/Getty Images)

Photographer Lori Nix hand-crafted dioramas are fictional scenes of a post-apocalyptic world in which plants and decay reclaim both grand and mundane structures. Each structure is built in Nix's living room and can take over half a year to build. Photo: Library, 2007. Photographer Lori Nix says this is the most popular image she has made for this project that she calls “The City”. (Photo by Lori Nix)