Armed Syrian Turkmen villagers are seen near the northern Syrian village of Yamadi, near the Turkish-Syrian border, Syria, November 24, 2015. Turkey shot down a Russian warplane near the Syrian border on Tuesday saying it had repeatedly violated its air space, one of the most serious publicly acknowledged clashes between a NATO member country and Russia for half a century. (Photo by Reuters/Stringer)

A groom leads his horse in the equine pool after working out on the track, during early morning workouts for the upcoming Derby race in Mumbai January 29, 2015. (Photo by Danish Siddiqui/Reuters)

Manuela (L) and Marta, members of the Revolutionary Armed Forces of Colombia (FARC), pose for a picture at a camp in the Colombian mountains on February 18, 2016. Many of these women are willing to be reunited with the children they gave birth and then left under protection of relatives or farmers, whenever the peace agreement will put an end to the country's internal conflict. (Photo by Luis Acosta/AFP Photo)

People attend a Halloween event at Ocean Park on October 30, 2015 in Hong Kong. Halloween – a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1 – a holiday when Christians remember their deceased loved ones. (Photo by Anthony Kwan/Getty Images)

An Iranian soldier guards two German tourists near the Iranian-Turkish border during World War II. Since the British occupation of Iran, all Axis nationals are being expelled from the country. (Photo by Three Lions/Getty Images). Circa 1941

The “Yama” (Pit) memorial is seen in the centre of Minsk May 5, 2015. The memorial is dedicated of the destruction of the Minsk ghetto during World War Two, when several hundred thousands of Jews were slaughtered. Belarus will mark Victory Day on May 9, the 70th anniversary of the Soviet Union's victory over Nazi Germany. (Photo by Vasily Fedosenko/Reuters)

This file photo provided on Sunday February 15, 2015 by the Syrian anti-government activist group Aleppo Media Center (AMC), which has been authenticated based on its contents and other AP reporting, shows Syrian rebels firing locally made shells against the Syrian government forces, in Aleppo, Syria. (Photo by AP Photo/Aleppo Media Center)

A Syrian Democratic Forces (SDF) female fighter adjusts a mortar in northern Deir al-Zor province ahead of an offensive against Islamic State militants, Syria February 21, 2017. (Photo by Rodi Said/Reuters)