A girl holds her brother in her arm as black smoke rises after an oil well set on fire in the center of al-Kayyara town to the south of Daesh terror organization-held Mosul in Iraq on October 25, 2016. The oil well in the center of al-Kayyara town, which was set alight by retreating Daesh militants in advance of the Iraqi army's takeover of the town on August 24, 2016 has still not entirely been put out. The raw petrol which is still alight is creating black clouds above the city. The residents and wildlife beneath this polluting smoke cloud may find their health at risk. The effects of the fire in the town center on unprotected civilians' health can easily be seen on the hands and faces of children playing on the street. (Photo by dris Okuducu/Anadolu Agency/Getty Images)

A Pomeranian dog sits in a rolling pet carrier in Hong Kong, China on September 4, 2019. (Photo by Kai Pfaffenbach/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.

People dressed as zombies participate in a parade for World Zombie Day 2016 in London's West End, Britain on October 9, 2016. (Photo by Splash News and Pictures)

A member of Four Paws International team carries a pelican to be taken out of Gaza, at a zoo in Khan Younis in the southern Gaza Strip August 23, 2016. Fifteen animals including a bengal tiger were removed from “the world’s worst zoo” in the Gaza town of Khan Younis as it was finally closed down. Animal welfare group, Four Paws International, will help bring most of the refugees to a zoo in Jordan, but the tiger will be taken to a refuge in South Africa. (Photo by Ibraheem Abu Mustafa/Reuters)

A man recieves a massage from a topless woman wearing a foxtail during the 61st annual Sturgis Motorcycle Rally August 7, 2001 in Sturgis, SD. Nudity is not permitted by the police, but airbrushing a woman''s nipples is sufficient to remain legal in the small town of 6,000. (Photo by David McNew/Getty Images)

An Egyptian passenger sits on the locomotive of a train as it leaves Cairo train station in Egypt, Wednesday, October 14, 2015. (Photo by Amr Nabil/AP Photo)

Passengers brave the strong winds as they wait for a bus, in Hong Kong, Monday, September 15, 2014. The Hong Kong Observatory issued the number 8 southeast storm signal, as Typhoon Kalmaegi edges closer to Hong Kong. (Photo by Kin Cheung/AP Photo)