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.

A competition, now in its 43rd year, dedicated to showcasing the beautiful and bizarre as seen under a light microscope attracted over 2,000 entries from 88 countries. Here: Honorable Mention by Emre Can Alagöz, Istanbul, Turkey: The eyes of a jumping spider, magnified 6x. (Photo by Emre Can Alagöz/2017 Nikon Small World Photomicrography Competition)

Underwater photographer Alexander Semenovs has snapped some of the most stunning, fragile life forms anywhere on planet Earth. Shot in deep, dark conditions, the images continue to provide an insight into what lies beneath, with glowing creatures appearing a lot like aliens in the pitch-black water. Semenovs has shot the likes of bioluminescent jellyfish, aggressive-looking worms and many species that leave a lot to the imagination. The 30-year-old from Moscow does the majority of his work in the White Sea, near the Arctic Circle. Here: A Comb jelly – Beroe cucumis. (Photo by Alexander Semenovs/Caters News)

Members of the traditional Los Historiantes dance group perform during a welcoming ceremony for Catholic devotees known as "Cumpas", in the town of Cuishnahuat, El Salvador November 26, 2015. The Catholic people of the El Balsamo mountain range meet in the village of Cuishnahuat in November to celebrate the 'friendship' between their respective patron saints in a ceremony that has been carried out for more than 300 years, according to the government. (Photo by Jose Cabezas/Reuters)

Comic club member Michael Kenney pauses on South Broad Street to adjust his costume during the 116th annual Mummers Parade in Philadelphia on Friday, January 1, 2016. Outrageously costumed Mummers strutted their stuff Friday at the city's annual New Year's Day parade, a colorful celebration that features string bands, comic brigades, elaborate floats and plenty of feathers and sequins. (Photo by Joseph Kaczmarek/AP Photo)

Stacked stones are pictured during the European Stone Stacking Championships 2018 in Dunbar, Scotland, on April 22, 2018. The European Stone Stacking Championships are Europe’s largest championships for all Stone Stacking and Rock Balancing artists and practitioners. The overall winner of the European Stone Stacking Championship will receive financial support for flights to the World Stone Balance Championship in Llano, Texas the following year. (Photo by Andy Buchanan/AFP Photo)

Fifty years ago, as France exploded in mass protests, words scrawled on the walls of the Sorbonne summed up the revolutionary zeal of the time: “Run free, comrade, we’ve left the old world behind!”. Sexual liberation, artistic creativity and anti-capitalism were the order of the day. For those who were there, it was an unforgettable time. Here: A wounded student is transported by first-aid workers during riots on the Boulevard Saint-Michel, Paris, France on May 6, 1968. (Photo by Gökşin Sipahioğlu/SIPA Press)

Born in 1958 in Abbazia, Italy, Frank Horvat is considered one of the founding fathers of French fashion photography. Frank Horvat: Storia di un Fotografo is on at Palazzo Chiablese Musei Reali, Turin, until 16 June. Here: Prostitutes, Bois de Boulogne, 1956. (Photo by Frank Horvat/The Guardian)