A Guarani Indian woman jokes with her son in the village of Pyau at Jaragua district, in Sao Paulo April 27, 2015. The National Indian Foundation (FUNAI) has recognised 521 hectares of this area as indigenous territory, making it the smallest indigenous reserve in Brazil. Members of the Guarani community have now established a new village outside the demarcation and are being threatened with an eviction through a court order. (Photo by Nacho Doce/Reuters)

A picture released by the North Korean Central News Agency (KCNA) shows Kim Jong-un convening an urgent operation meeting at 0:30 am on March 29, 2013 at an undisclosed location, in which he ordered strategic rocket forces to be on standby to strike US and South Korean targets at any time. (Photo by KCNA via EPA)

Reuters multi-award winning photographers are celebrated here in a three part retrospective on the 30th anniversary of the service's launch. They have captured dramatic images illustrating the human tragedy of natural disaster and war as well as the fallout of economic events across the continents, creating iconic images, recognised around the world. Here: an injured soccer fan is carried to safety by a friend after a wall collapsed during violence between fans before the European Cup final between Juventus and Liverpool at the Heysel stadium in Brussels, May 29, 1985. 39 people died, and a further 600 were injured. (Photo by Nick Didlick/Reuters)

A student activist is detained during a silent protest after Thailand's election commission filed charges against a group for posting “foul and strong” comments online criticising a military-backed draft constitution, in Bangkok, Thailand April 27, 2016. (Photo by Jorge Silva/Reuters)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

Joshua Patino stands on a ladder to put finishing touches on a giant dinosaur exhibit at PAX East in the Boston Convention and Expo Center, Thursday, April 21, 2016, in Boston. PAX East, an annual celebration of gaming culture, is expected to draw tens of thousands of visitors Friday through Sunday. It's a place where serious gamers can preview unreleased video games and devices, compete in tournaments, hear live music and meet others for whom gaming is a way of life. (Photo by Elise Amendola/AP Photo)

Paramilitary policemen carry tyres as they take part in a training session in Zhangye, Gansu Province, China, March 1, 2016. (Photo by Reuters/Stringer)