Farmers herd a flock of ducks along a street towards a pond as residents drive next to them in Taizhou, Zhejiang province, June 17, 2012. (Photo by Reuters/China Daily)

A basket of olives sits in an olive tree field in La Rinconada, near the Andalusian capital of Seville September 24, 2012. (Photo by Marcelo del Pozo/Reuters)

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.

Stray dogs stand on tombs in Diamond Hill cemetery in Hong Kong, China, 04 April 2017. According to the lunar calendar, the Qingming Festival is observed on 04 April . The Qingming Festival, also known as Tomb-Sweeping Day, is marked by Chinese people by going to the cemetery to cleaning up tombs, bring flowers, and making offerings to their ancestors. (Photo by Jerome Favre/EPA)

Charli XCX performs at Hype Hotel on March 17, 2016 in Austin, Texas. (Photo by Lorne Thomson/Redferns)

A man flies a kite made of 110 Tukkal or paper lanterns for the Hindu festival of “Makar Sankranti”, which marks the start of spring, in Ahmedabad January 13, 2011. (Photo by Amit Dave/Reuters)

Visitors wear shirts with an image of former Chinese leader Mao Zedong at the Shanghai World Expo site in Shanghai, May 2, 2010. (Photo by Aly Song/Reuters)

This photo taken on December 2, 2015 shows a lenticular cloud forming as white streaks from airplanes mark the blue sky, in a rare atmospheric phenomena above the town of Gevgelija on December 2, 2015. Lenticular clouds have been regularly confused for UFOs throughout history due to the their smooth, round or oval lens-shaped structure. (Photo by Armend Nimani/AFP Photo)