Boys pan for gold on a riverside at Iga Barriere, 25 km (15 miles) from Bunia, in the resource-rich Ituri region of eastern Congo February 16, 2009. Ituri is one of many areas of the country to have experienced bitter ethnic conflict between rival tribes in recent years. Massacres have left tens of thousands dead. It is this fighting that led U.S. authorities to take the unprecedented step of naming Congo in section 1502 of the Dodd-Frank financial regulation act, which says U.S.-listed companies that source gold, tungsten, tantalum and tin from Congo or its neighbours must assure the U.S. stock exchange regulator that their business is not helping fund conflict. (Photo by Finbarr O'Reilly/Reuters)

Wrestler known as Gio Malkriado (top) fights with a fluorescent tube with wrestler Ciclope during an extreme wrestling fight at a temporary wrestling ring inside a car wash in Tulancingo Hidalgo, Mexico October 8, 2016. When the time comes for the so-called Extreme Star Fight, six wrestlers climb into the ring. Once the fighting begins, anything goes. They bash each other with chairs and long neon lights, causing small explosions and scattering tiny pieces of glass everywhere. (Photo by Carlos Jasso/Reuters)

Soldiers are reflected in a puddle during a military parade during the celebrations for Romania's National Day in Bucharest December 1, 2014. (Photo by Radu Sigheti/Reuters)

An activist kicks the shields of the military police officers during a demonstration in the military zone of the 27th infantry battalion in Iguala, Guerrero, January 12, 2015. Activists and relatives of the 43 missing trainee teachers from Ayotzinapa's teacher training college broke into the military zone, located less than a mile from where the students went missing, in an attempt to look for the missing students.The remains of only one of the 43 students has been identified so far. (Photo by Jorge Dan Lopez/Reuters)

A demonstrator attends a protest against fare hikes for city buses in Rio de Janeiro January 16, 2015. Amid a marked economic downturn and high inflation, bus fares went up in Sao Paulo, Brazil's largest city, from 3 to 3.50 reais, and in Rio, the former capital, from 3.0 to 3.40 reais. (Photo by Mauro Pimentel/Reuters)

A gaucho is unseat by a wild horse during the annual celebration of Criolla Week in Montevideo, March 30, 2015. Throughout Easter Week, “gauchos”, the Latin American equivalent of the North American cowboy, from all over Uruguay and neighboring Argentina and Brazil will visit Montevideo to participate in the Criolla Week to win the best rider award. The competition is held from March 29 to April 5 this year. (Photo by Andres Stapff/Reuters)

A colourful sky before sunrise on Whitley Bay beach on December 21, 2015, as December could be the mildest across a large part of England since records began more than 350 years ago, forecasters have said. (Photo by Owen Humphreys/PA Wire)

Hot air balloons take part in the 38th International Balloon Festival of Chateau-d'oex, Switzerland, 23 January 2016. For nine days balloonists from 15 countries take part in the ballooning event in the Swiss mountain resort famous for ideal flight conditions due to an exceptional microclimate. The festival takes place from 23 to 31 January. (Photo by Cyril Zingaro/EPA)