A US Army M1A2 SEP tank participates in the Strong Europe Tank Challenge 2017 at the military training area in Grafenwoehr, Germany, 12 May 2017. Six North Atlantic Treaty Organization (NATO) nations and partner nations, Austria, France, Germany, Poland, Ukraine and the USA are taking part in this competing exercise. (Photo by Christian Bruna/EPA)

An Afghan man rides on his donkey, holding balloons for sale during Newroz Day celebrations, a festival marking their spring and new year, in Kabul, Afghanistan March 21, 2017. (Photo by Omar Sobhani/Reuters)

A woman prays as she touches the carcass of a male elephant after he, according to forest officials, was electrocuted early morning in a paddy field on the outskirts of Guwahati, India, June 20, 2017. (Photo by Anuwar Hazarika/Reuters)

Nicki Minaj performs on stage during the 2017 NBA Awards Live On TNT on June 26, 2017 in New York City, USA. (Photo by Michael Loccisano/Getty Images for TNT)

Syrian Internal Security Forces dance in celebration during their graduation ceremony, at Ain Issa desert base, in Raqqa province, northeast Syria, Thursday, July 20, 2017. Some 250 residents of Syria's Raqqa province are the latest batch to graduate from a brief U.S-training course that is preparing an internal security force to hold and secure areas as they are captured from Islamic State militants. (Photo by Hussein Malla/AP Photo)

A man wearing a mask and dressed in a clown costume rides an electric tricycle while carrying a container in the shape of a rubber duck amid heavy smog in Beijing, China, December 29, 2015. (Photo by Jason Lee/Reuters)

An Afghan teacher, in brown, helps school children run from the site of clashes near the Pakistan consulate in Jalalabad, capital of Nangarhar province, Afghanistan, Wednesday, January 13, 2016. Several members of the Afghan security forces were killed Wednesday after unidentified gunmen attacked the Pakistani consulate in a volatile eastern province, an official said on Wednesday. (Photo by Mohammad Anwar Danishyar/AP Photos)

A woman selling souvenirs walks through Kuta beach in Bali June 5, 2008. Indonesia is expected to report tourist arrivals in December this week. (Photo by Murdani Usman/Reuters)