A Pegasus airplane is seen stuck in mud as it skidded off the runway after landing in Trabzon Airport, Turkey early Sunday on January 14, 2018. A passage plane which belongs to Turkey's Pegasus Airlines skidded off the runway of Trabzon airport Saturday and ended up halfway down a steep slope into the Black Sea, Turkish media reported on Sunday. 162 passengers and crew on board were safely evacuated. (Photo by Hakan Burak Altunoz/Anadolu Agency/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.

An art installation formed with milk churns, made by land art artist Gerard Benoit a la Guillaume, is seen at the Chenau de Mayen in the resort of Leysin, Switzerland August 7, 2015. More than 80 milk churns were placed between the Tour d'Ai and the Tour de Mayen summits at an altitude of 2,000 meters (6,561 feet) above sea level under the direction of the artist, to be photographed for his ongoing art project entitled “Milk churns without borders”. (Photo by Denis Balibouse/Reuters)

Rabbits are seen in a cage, which is placed by authority as a test of the living conditions near the site of last week's blasts at Binhai new district in Tianjin, China, August 19, 2015. According to local media, the animals were alive after being placed near the blasts site for two hours. Four new fires have broken out at the site where two huge blasts last week killed 116 people, Chinese state media reported Friday soon after officials said safety hazards were found at almost 70 percent of firms handling dangerous chemicals in Beijing. (Photo by Reuters/Stringer)

A man fires a weapon as he dances during a traditional excursion near the western Saudi city of Taif, August 8, 2015. Saudis usually party in such excursions as they celebrate weddings or graduations. (Photo by Mohamed Al Hwaity/Reuters)

Military policemen take part in an operation at Cidade de Deus favela in Rio de Janeiro, Brazil, on February 01, 2018. (Photo by Mauro Pimentel/AFP Photo)

This handout photograph taken and released by Limex Images for Red Bull on February 6, 2019 shows France's Nicolas Ivanoff flying over the skyline prior to the first stage of the Red Bull Air Race World Championship in Abu Dhabi, United Arab Emirates. (Photo by Predrag Vuckovic/AFP Photo)

Metropolitan Transit Authority (MTA) Police Officer Keith Flood trains with his K-9 partner Doc, a German Shepherd, inside the “warehouse room” at the new MTA Police Department Canine Training Center in Stormville, New York, U.S., June 6, 2016. (Photo by Mike Segar/Reuters)