A worker paints the Amazon Tall Tower Observatory (ATTO) in Sao Sebastiao do Uatuma in the middle of the Amazon forest in Amazonas state January 10, 2015. The Amazon Tall Tower Observatory is a project of Brazil's National Institute of Amazonian Research and Germany's Max Planck Institute and will be equipped with high-tech instruments and an observatory to monitor relationships between the jungle and the atmosphere from next July. According to the institutes, ATTO will gather data on heat, water, carbon gas, winds, cloud formation and weather patterns. (Photo by Bruno Kelly/Reuters)

U.S. soldiers wrestle with South Korean soldiers in a muddy ring during a joint ranger training exercise at a ranger camp near the demilitarised zone (DMZ) June 25 2003 in Paju, South Korea. (Photo by Chung Sung-Jun/Getty Images)

Members of the South Korean Special Weapons and Tactics team exhibit their skill during anti-terrorism exercises at a training camp on May 30, 2005 in Seoul, South Korea. (Photo by Chung Sung Jun/Getty Images)

A man runs away during a police round up of suspected drug addicts in Kabul, Afghanistan December 27, 2015. Afghan officials have opened a new drug treatment centre in an abandoned NATO military base in Kabul, in the latest attempt to stamp out the country's massive problem of drug abuse. Camp Phoenix, a former training camp on the edges of Kabul set up by the U.S. army in 2003, will take in around 1,000 homeless drug addicts who will receive food, medical attention and treatment, said Public Health Minister Ferozuddin Feroz. (Photo by Ahmad Masood/Reuters)

A resident carries a gas canister as an ash cloud hovers above during an eruption of Mount Sinabung volcano at Tiga Serangkai village in Karo Regency, North Sumatra province, Indonesia June 24, 2015. More than 10,000 people from 12 villages, who are living around the slopes of Mount Sinabung, left their homes and moved to refugee camps, local media reported. (Photo by Reuters/Beawiharta)

Young Palestinians form an obstacle to be jumped over during a military-style exercise graduation ceremony organised by the Hamas movement, in Gaza City August 5, 2015. Thousands of young Palestinians joined Hamas military-style summer camps during school vacation in the Gaza Strip to prepare them to “confront any possible Israeli attack”, organisers said. (Photo by Suhaib Salem/Reuters)

A member of the Hindu nationalist Rashtriya Swayamsevak Sangh (RSS) or the National Volunteers Association keeps watch from the top of a tree as others sit on the ground during their daylong camp on the outskirts of Pune, Maharashtra state, India, Sunday, January 3, 2016. Hindus, make up more than 80 percent of India's population of 1.25 billion. (Photo by Rafiq Maqbool/AP Photo)

A man holds a metal bar as a weapon during a training day for former soldiers and volunteers train in a makeshift camp in the outskirts of Port-au-Prince, Haiti, October 28, 2015. Haiti disbanded its abusive armed forces two decades ago but uniformed veterans and young recruits are resurfacing to add another destabilising factor to the volatile Caribbean nation already dealing with a political vacuum. (Photo by Andres Martinez Casares/Reuters)