Participants with traditional Japanese tattoos (Irezumi), related to the Yakuza, walk through the Asakusa district during the annual Sanja Matsuri festival in Tokyo on May 20, 2018. Sanja Matsuri festival is a celebration for the three founders of Sensoji Temple in the Asakusa neighbourhood with nearly two million people visiting during the three-day event. (Photo by Behrouz Mehri/AFP Photo)

An Egyptian boy holds a camel at the Berqash camel market northeast of Cairo, on August 17, 2018. Muslims across the world are preparing for the Eid al-Adha holiday when custom requires the faithful to make a sacrifice. (Photo by Khaled Desouki/AFP Photo)

Police officers laugh as Greenpeace activists create a burnt smoldering rain-forest with a lifelike animatronic orangutan at the headquarters of Oreo cookies, in protest over their use of palm oil on November 19, 2018 in Uxbridge, England. Greenpeace is calling on the makers of Oreo to stop buying palm oil from Wilmar, the largest palm oil producer, who they say have destroyed 70,000 hectares of Indonesian rain forest in the last two years. (Photo by Chris J. Ratcliffe for Greenpeace via Getty Images)

University students demonstrate against the crisis in the public education, budget cuts and a tax reform project announced by the government of Ivan Duque in Medellin, Colombia on December 13, 2018. (Photo by Joaquín Sarmiento/AFP Photo)

Dozens of people participate in the religious pilgrimage to the National Shrine of El Rincon, in the municipality of Boyeros, in Havana, Cuba, 17 December 2018. As is customary every year, thousands of people in mass attend the shrine to pay tribute to Saint Lazarus, to whom the faithful come for personal requests and miracles. (Photo by Ernesto Mastrascusa/EPA/EFE)

Indian women wearing traditional attire take a “selfie” with an Indian man dressed as King 'Mahabali' during the Hindu harvesting festival Onam celebrations in Bangalore, India, 28 August 2015. Local people put flower mats in front of their houses, to welcome the King Mahabali, a past ruler of Kerala southern India, during the ten-day festival. (Photo by Jagadeesh N. V./EPA)

A string is used to ensure that the skirts of female members of the honour guard are in the same height from the ground as they prepare for a welcoming ceremony for Congo Republic President Denis Sassou Nguesso outside the Great Hall of the People in Beijing, China, July 5, 2016. (Photo by Jason Lee/Reuters)

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)