Passengers from the ferry sinking off South Korea's southern coast are rescued by the South Korean Coast guard in the water off the southern coast near Jindo, south of Seoul, on April 16, 2014. Almost 300 people were missing after a ferry sank off South Korea on Wednesday, the coastguard said, in what could be the country's biggest peacetime disaster in nearly 20 years. (Photo by 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.

Japan Self-Defense Force members pay their respect to unidentified earthquake victims in vehicles during a mess funeral on April 8, 2011 in Yamamoto, Miyagi Prefecture, Japan. The 9.0 magnitude strong earthquake struck offshore on March 11 at 2:46pm local time, triggering a tsunami wave of up to ten metres which engulfed large parts of north-eastern Japan, and also damaging the Fukushima nuclear plant and threatening a nuclear catastrophe. The death toll continues to rise with numbers of dead and missing exceeding 20,000 in a tragedy not seen since World War II in Japan. (Photo by Athit Perawongmetha/Getty Images)

“Rescuers were digging through mud and debris Friday to retrieve more bodies strewn across a farming valley in the southern Philippines by a powerful typhoon. The death toll from the storm has surpassed 500, with more than 400 people missing”. – Bullit Marquez via Associated Press

Photo: Children look at the a damaged road destroyed by flash floods at the height of Typhoon Bopha in the village of Andap, New Bataan town, Compostela Valley province, December 5, 2012. (Photo by Ted Aljibe)

The number of soldiers on both sides of WWII that were killed or went missing is just staggering. Now, the mystery surrounding one RAF pilot and what happened to him and his plane has been solved after 70 years. RAF flight Sergeant Dennis Copping climbed into his Kittyhawk P-40 aircraft in June 1942 to fly the plane to another airbase for repairs. He was never seen or heard from again.

These images show off some of the world's most majestic creatures silhouetted against the beautiful rising and setting sun. The vibrant pictures feature a variety of animals in the wild and were taken by a host of photographers at locations around the world. The striking images all have one thing in common: the photographers' awe-inspiring ability to perfectly capture the silhouettes of earth's beautiful creatures. Here: a blue wildebeest moves through grassland at dawn with the sun in the background in Mara Naboisho Conservancy, Kenya, Africa. (Photo by Renato Granieri/Caters News/Ardea)

These snaps capture true winter wonderlands – as Mother Nature's icy grip takes hold of America's National Parks. From snow-capped mountains in Yosemite to an icy still Glacier Bay, the incredible images show their beauty is year round. In other breath-taking shots crisp frost lines the paths through Great Smokey Mountains and Crater Lake has had more than a dusting of snow. Here: Apostle Island National Lakeshore Park in Wisconsin. (Photo by U.S. Department of the Interior/Cater News)

A selection of hand-made leis, traditional Hawaiian necklaces made of flowers and worn mostly on special occasions, fill a cooler at Lin's Lei Shop in the Chinatown district of Honolulu, Hawaii December 22, 2015. Hawaii, whose economy depends heavily on tourism, sees a brief lull in visitors each year in January and February. But in addition to the usual tourist destinations, the state shows a unique overlay of mainland U.S. culture atop tropical beauty year-round. (Photo by Jonathan Ernst/Reuters)