A machine works on a Rio 2016 Olympic medal at the Casa da Moeda do Brasil (Brazilian Mint) in Rio de Janeiro, Brazil, June 28, 2016. The Casa da Moeda do Brasil is the Brazilian mint, owned by the Brazilian government and administratively subordinated to the Ministry of Finances. It was established in 1694. (Photo by Sergio Moraes/Reuters)

Workers carry sacks of tea leaves at a tea estate in Nagaon district in the northeastern state of Assam, India, August 22, 2016. (Photo by Reuters/Stringer)

In this September 1, 2016 photo, 90-year-old street vendor Antonio Bauza waits for tourists to sell his bananas, next to the village church in Remedios, Cuba. With the arrival of the first commercial flights from the U.S. to Cuba in more than 50 years, the Cuban government is welcoming the wave of new visitors and struggling to update infrastructure that's already overwhelmed. (Photo by Ramon Espinosa/AP Photo)

Palestinian children warm themselves by a fire on a stormy day at Shati (beach) refugee camp in Gaza City January 18, 2016. (Photo by Mohammed Salem/Reuters)

A police officer detains a woman on suspicion of collaborating with the 18th street gang during a "Safe House" operation at the Concepcion neighbourhood in San Salvador, July 2, 2015. Salvadoran police make “Safe House” operations at dangerous neighbourhoods of the capital to prevent murders, according to local media. (Photo by Jose Cabezas/Reuters)

Labourers carry a basket packed with vegetables through a wholesale market in Kolkata, India, February 26, 2016. (Photo by Rupak De Chowdhuri/Reuters)

A man exercises in the early morning on a hilltop overlooking Kabul, Afghanistan March 3, 2016. (Photo by Mohammad Ismail/Reuters)

People wash in water from a broken water pipeline on the outskirts of Kolkata, India, March 30, 2016. (Photo by Rupak De Chowdhuri/Reuters)