Children play in an outdoor shower as a soldier takes part in a surprise operation in the Manguinhos slum in Rio de Janeiro, Brazil, Thursday, January 18, 2018. Troops have been sent to Rio due to the increase of the violence, and in an attempt to help restore order, but so far have had little impact. The operation on Thursday took place three weeks ahead of Carnival, when thousands of tourists are expected to arrive in the city. (Photo by Leo Correa/AP Photo)

A North Korean soldier throws a stone towards a photographer on the banks of the Yalu River in the North Korean town of Sinuiju, opposite the Chinese border city of Dandong October 21, 2006 in Sinuiju, Democratic People's Republic of Korea. (Photo by Cancan Chu/Getty Images)

A female forest guard carries a tranquillizer gun in the Gir National Park and Wildlife Sanctuary in Sasan, in Gujarat December 2, 2014. The sanctuary, which is home to Asiatic lions in India, has an area of 1,412 sq km in which female guards were employed for the first time in India in 2007. The guards fetch a monthly salary of around $148 for working almost 12 hours a day, six days a week, said one of the female guards. (Photo by Anindito Mukherjee/Reuters)

Blacksmith Johann Schmidberger works on a suit of armour for the Vatican's Swiss Guards at his workshop in Molln, Austria, March 29, 2017. Austrian blacksmiths who produce ceremonial suits of armour for the Vatican's Swiss Guards are close to the end of their current deal to do so, and say supplying the suits will not now be an issue for many years to come. One of the drawbacks of the Swiss Guards' medieval uniforms is that the craftsmanship needed to make them is disappearing. (Photo by Leonhard Foeger/Reuters)

Dominic Bergamin, left, a new Vatican Swiss Guard, is is kissed by his wife Joanne, prior to a swearing-in ceremony, at the Vatican, Wednesday, May 6, 2015. The ceremony is held each May 6 to commemorate the day in 1527 when 147 Swiss Guards died protecting Pope Clement VII during the Sack of Rome. (Photo by Ettore Ferrari/AP Photo/Pool Photo)

A military police officer patrols in the Roquette Pinto shantytown, part of the Mare slum complex in Rio de Janeiro, Brazil, Wednesday, April 1, 2015. The Brazilian army has begun to pull out of one of Rio de Janeiro's most violent slums, with police assuming responsibility for security in the area. (Photo by Felipe Dana/AP Photo)

NATO and U.S. flags flutter as U.S. Air Force F-22 Raptor fighter flies over the military air base in Siauliai, Lithuania, April 27, 2016. (Photo by Ints Kalnins/Reuters)