The painted nails of a Kurdish Peshmerga female fighter are seen as she takes up a position during combat skills training before being deployed to fight Islamic State militants, at their military camp in Sulaimaniya, northern Iraq September 18, 2014. (Photo by Ahmed Jadallah/Reuters)

Members of the Al-Baraa bin Malek batallion, part of the Free Syria Army's Al-Fatah brigade, duck to the ground as they pull a man (R) who was shot by a sniper twice in the Bustan al-Basha district of the northern city of Aleppo on October 20, 2012. (Photo by Javier Manzano/AFP Photo)

Bikers push their motorbikes during a traffic block as they take part in the “Enduropale” motorcycle endurance race on the beach of Le Touquet, northern France, February 1, 2015. About 1100 motorbike and 600 quad bike riders descend on Le Touquet every year for the racing endurance event. (Photo by Pascal Rossignol/Reuters)

Members of the Oath Keepers and general public return fire during a simulated attack as they take part in a tactical training session in northern Idaho, U.S. October 1, 2016. In April 2015 Reuters photographer Jim Urquhart was assigned to cover the Oath Keepers during a tour of the Sugar Pine gold mine in Oregon after the group of former cops, military, firefighters and other first responders had risen to prominence during a standoff in Nevada over land rights. (Photo by Jim Urquhart/Reuters)

Syrian civil defence volunteers, known as the White Helmets, rescue a boy from the rubble following a reported barrel bomb attack on the Bab al- Nairab neighbourhood of the northern Syrian city of Aleppo on November 24, 2016. (Photo by Ameer Alhalbi/AFP Photo)

Paul, 9, dumps a bucket of water over his head at a fountain near government buildings during hot weather on July 1, 2015 in Berlin, Germany. Temperatures across northern Europe are rising and in Germany a high of 36 degrees is forecast for the weekend. (Photo by Sean Gallup/Getty Images)

A female swimmer reacts after finishing the competition in a pool carved from thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province, January 5, 2016. The swimming competition was held on the official launch day of the Harbin International Ice and Snow Sculpture Festival. (Photo by Aly Song/Reuters)

A child uses an umbrella to avoid rain falling on a fire at the northern Greek border point of Idomeni, Greece, Monday, April 25, 2016. Many thousands of migrants remain at the Greek border with Macedonia, hoping that the border crossing will reopen, allowing them to move north into central Europe. (Photo by Gregorio Borgia/AP Photo)