An Indian artist performs with fire during a procession as part of “Bonalu” festival in Hyderabad, India, Monday, Aug.10, 2015. Bonalu is a month long Hindu folk festival of India's Telangana region dedicated to Kali, the Hindu goddess of destruction. (Photo by Mahesh Kumar A./AP 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.

In this photograph taken on June 28, 2015, a hiker in Hong Kong takes a picture of the city from a walking trail. The southern Chinese territory is crisscrossed by more than 180 miles of designated hiking trails. (Photo by Alex Ogle/AFP Photo)

Culinary Specialist 2nd Class Jaqueline Rodriguez subdues a simulated suspect after being sprayed with oleoresin capsicum (OC) spray during security training aboard the amphibious dock landing ship USS Comstock (LSD 45). (U.S. Navy photo by Mass Communication Specialist 2nd Class Joseph M. Buliavac/Released). May 10, 2011

A driver on the Horseshoe Pass in North Wales wiping the snow from the windscreen of his car during a heavy snow storm, 18th January 1937. (Photo by Norman Smith)

Members of the Wasteland Warriors from the movie “MadMax” pose during the Wacken Open Air festival on August 4, 2016 in Wacken, Germany. Wacken is a village in northern Germany with a population of 1,800 that has hosted the annual festival, which attracts heavy metal fans from around the world, since 1990. (Photo by Alexander Koerner/Getty Images)

A workman smooths out the gravel near the base of British artist Alex Chinneck' latest sculpture “A bullet from a shooting star” on the Greenwich Peninsula in London on September 17, 2015. The 35-metre tall, upside-down electricity pylon overlooks the Canary Wharf financial district. (Photo by Leon Neal/AFP Photo)

A man runs after he tried to put himself on fire during a protest at a makeshift camp at the Greek-Macedonian border near the village of Idomeni on March 22, 2016. Greece will not be able to start sending refugees back to Turkey from March 20, 2016, the government said, as the country struggles to implement a key deal aimed at easing Europe's migrant crisis. The numbers are daunting: officials said as of Saturday there were 47,500 migrants in Greece, including 8,200 on the islands and 10,500 massed at the Idomeni camp on the Macedonian border. (Photo by Andrej Isakovic/AFP Photo)