The Rio de Janeiro Olympics kick off on August 5 for some two weeks of competitive games drawing athletes as well as audiences from around the world. As they prepare to cover the event, Reuters photographers look back on their favourite pictures from past Olympics where they captured the action on the ground as well as the participants' tears and joy that followed. (Photo by Lucy Nicholson/Reuters)

Zurich soccer player Loris Benito tries to catch a marten during the Swiss Super League match between FC Thun and FC Zurich in Thun, Switzerland, March 10, 2013. (Photo by Marcel Bieri/Keystone)

In this Friday, March 28, 2014 photo, singers of the Moranbong Band, Jong Su Hyang, foreground, and Pak Mi Kyong, left perform on their stage in Pyongyang, North Korea. Step aside, Sea of Blood Opera. North Korean leader Kim Jong Un's favorite guitar-slinging, miniskirt-sporting girl group, the Moranbong Band, is back. And these ladies know how to shimmy. (Photo by Jon Chol Jin/AP Photo)

Handout grab taken from YouTube of Commander Chris Hadfield who has said goodbye to life on the International Space Station by making a cover version of David Bowie's Space Oddity. Issue date: Monday May 13, 2013. (Photo by Commander Chris Hadfield/YouTube/PA Wire)

The electronically animated giant baby Miguelin (created by Isabel Coixet in collaboration with the special effects team behind Alien vs. Predator) was seen in the Spanish Pavilion at the site of Shanghai 2010 World Expo on April 27, 2010 in Shanghai, China. (Photo by China Photos)

Karl Templer styles Katy Perry as icon of Hollywood glamour Elizabeth Taylor for the March cover editorial of Interview Magazine. Mikael Jansson captures the newly-divorced, almost unrecognizable pop star in a visually stunning set of marvelous images. (Photo by Mikael Jansson)

“Dog fighting is a form of blood sport in which game dogs are made to fight, sometimes to the death. It is illegal in most developed countries. Dog fighting is used for entertainment and may also generate revenue from stud fees, admission fees and gambling”. – Wikipedia

Photo: A bloody Afghan dog is bleeding with many wounds after he lost a dog fight November 24, 2006 in Kabul, Afghanistan. While the Afghan government is trying to ban the violent use of dogs for fighting, the unofficial sport remains a regular weekly event. Afghan dog fighting is popular among Afghan men who gamble on the dogs making upwards of 15,000 Afghanie (300 USD). (Photo by Paula Bronstein/Getty Images)

A radio-controlled flying witch makes a test flight past a moon setting into clouds along the pacific ocean in Carlsbad, California October 8, 2014. Reuters was invited to photograph the testing of the life sized device by inventor Otto Dieffenbach lll. (Photo by Mike Blake/Reuters)