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.

Yannis Behrakis, one of Reuters' most decorated and best-loved photographers, has passed away after a long battle with cancer. He was 58. Here: A pro-government Sierra Leonean fighter bites a bullet as he takes position in no man's land 2 km ahead of Rogberi junction where evidence of executed UN troops were found after heavy fighting between government troops and RUF rebels 100 km north east of Freetown, Sierra Leone, May 23, 2000. (Photo by Yannis Behrakis/Reuters)

Natalie Dormer attends the mtvU Fandom Awards at MTV Fan Fest at Comic-Con, July 24, 2014, in San Diego. (Photo by Jordan Strauss/Invision for MTV/AP Images)

People take pictures of 30 Rockefeller Plaza as it is lit in the colors of the Democratic and Republican parties ahead of the U.S presidential election in Manhattan, New York, U.S., November 7, 2016. (Photo by Andrew Kelly/Reuters)

South Korean university students prepare for an establishment ceremony of the Reserve Officer Training Corps (ROTC) for female cadets at Sookmyung Women's University on December 10, 2010 in Seoul, South Korea. The South Korean defense ministry has agreed to admit women into it's college-based Reserve Officers' Training Program for the first time since the program began in 1963. (Photo by Chung Sung-Jun/Getty Images)

“Sasha Grey (born Marina Ann Hantzis on March 14, 1988) is an American former pornographic actress, who has since turned to mainstream acting, modeling and music. Early in her adult film career, she was profiled by several popular culture magazines and television programs. She won several AVN Awards between 2007 and 2010, and has also been featured in music videos and advertising campaigns. After her mainstream feature film debut as the lead in Steven Soderbergh's The Girlfriend Experience, she shifted her focus to acting, starring in the black comedy/horror film Smash Cut as April Carson, as well as having a supporting role in season 7 of HBO's Entourage. She has also appeared in independent films Quit, The Girl from the Naked Eye, and Mark Pellington's I Melt With You”. – Wikipedia

Photo: Actress Sasha Grey arrives at the premiere of “127 Hours” at the Academy Of Motion Picture Arts and Sciences Samuel Goldwyn Theater on November 3, 2010 in Beverly Hills, California. (Photo by Jason Merritt/Getty Images)

Yuccas catch fire as the Powerhouse fire makes a fast run toward Lake Hughes, south of Lake Hughes, California, on June 1, 2013. The 19,500-acre wildfire destroyed numerous homes overnight. (Photo by David McNew/Getty Images)