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)

An Iraqi soldier stands guard as a pipeline burns in the background after an explosion 30 kilometers (20 miles) northeast of Tikrit, Iraq, Monday, February 11, 2008. (Photo by Bassem Daham/AP Photo)

A Pasola rider reacts after throwing his spear during the Pasola war festival at Ratenggaro village on March 22, 2014 in Sumba Island, Indonesia. The Pasola Festival is an important annual event to welcome the new harvest season, which coincides with the arrival of “Nyale” sea worms during February or March each year. Pasola, an ancient ritual fighting game, involves two teams of men on horseback charging towards each other while trying to hit their rivals with “pasol” javelins and avoid being hit themselves. (Photo by Ulet Ifansasti/Getty Images)

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 suspected street robber is arrested by a policeman after a brief chase in the streets, June 20, 2016, in Manila, Philippines. The president-elect of the Philippines, Rodrigo Duterte, declared a war on crime and drugs after sweeping an election on May 9 and has been living up to his nickname, “the punisher”. Philippine police have been conducting night raids almost on a daily basis and revived a curfew for minors that had not been enforced for years, rounding up minors drinking on the streets. (Photo by Dondi Tawatao/Getty Images)

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)

A man holds a cow at the cattle market in Maiduguri, Nigeria, March 9, 2016. A Nigerian government push to strangle the Boko Haram insurgency has shut down the cattle trade that sustained the city of Maiduguri, leaving many residents with no livelihood, including many of the two million people displaced by the war. In recent months the army has taken back much of the territory lost to the jihadists during the five-year insurgency. (Photo by Afolabi Sotunde/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)