Commonwealth dance group on the right track with Virgin Trains – Photo call at Glasgow Central Station. (Photo by Daily Record)

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.

Timbuktu: A UN peacekeeper from Burkina Faso stands guard at the Djinguereber mosque, built in the 14th century, during a visit by a UN delegation on election day in Timbuktu, Mali, July 28, 2013. (Photo by Joe Penney/Reuters)

A girl uses her mobile phone during the evening at the National Park in Khartoum, Sudan, April 24, 2015. (Photo by Mohamed Nureldin Abdallah/Reuters)

A trader speaks on the phone at his desk at the Frankfurt stock exchange, Germany, in this June 29, 2015 file photo. Federal Reserve policymakers are widely seen raising interest rates for the first time in almost a decade at their next meeting this week. (Photo by Ralph Orlowski/Reuters)

An Airbus A380 aircraft prepares to land at Mumbai airport in this May 8, 2007 file photo. Sentiment at some of Asia's biggest firms deteriorated again in the fourth quarter, falling to a four-year low under the weight of concerns about slowing growth in China, the region's biggest economy, a Thomson Reuters/INSEAD survey showed. (Photo by Arko Datta/Reuters)

A conductor (C) collects fares from candy floss sellers as they travel in a tram to a marketplace early morning in Kolkata, India, December 23, 2015. (Photo by Rupak De Chowdhuri/Reuters)

A woman photographs a Norwegian spruce Christmas tree from Oslo after it was lit at Trafalgar Square in central London, December 4, 2014. (Photo by Toby Melville/Reuters)