Internally displaced Syrian children play inside a refugee camp in the Hama countryside, Syria January 1, 2016. (Photo by Ammar Abdullah/Reuters)

An injured boy who is undergoing surgery, after he was injured in what activists said was an airstrike by forces loyal to Syria's president Bashar al-Assad, rests inside a field hospital in the Douma neighborhood of Damascus, Syria December 5, 2015. Douma in Syria, an area controlled by rebels fighting to topple President Bashar al-Assad, has been shelled continuously for the past three years. The injured are taken to basements and shelters transformed into field hospitals run by medical staff who have stayed in the battered neighbourhood of Damascus. (Photo by Bassam Khabieh/Reuters)

Iranian Kurdish female members of the Freedom Party of Kurdistan (PAK) hold a position on November 6, 2016 in an area near the town of Bashiqa, some 25 kilometres north east of Mosul, during an operation against Islamic State (IS) group jihadists to retake the main hub city. (Photo by Safin Hamed/AFP Photo)

Kurdish guard women from the civilian protection unit which supports the Democratic Forces of Syria, cheer near the Syrian town of al Houl in Hasaka province, after the Democratic Forces of Syria took control of the area, November 14, 2015. A U.S.-backed Syrian rebel alliance on Friday captured the town of al Houl in Hasaka province, which had been held by Islamic State militants, a spokesman for the Kurdish fighters, part of the grouping, said. It was the first significant advance against IS by the Democratic Forces of Syria, which was formed last month. (Photo by Rodi Said/Reuters)

A man takes a selfie in front of a fire from oil that has been set ablaze in the Qayyarah area, some 60 kilometres (35 miles) south of Mosul, on October 19, 2016, during an operation by Iraqi forces against Islamic State (IS) group jihadists to retake the main hub city. In the biggest Iraqi military operation in years, forces have retaken dozens of villages, mostly south and east of Mosul, and are planning multiple assaults for October 20. (Photo by Yasin Akgul/AFP Photo)

Actors perform a scene in a film directed by Humam Husari in the rebel-held besieged town of Zamalka, in the Damascus suburbs, Syria September 19, 2016. (Photo by Bassam Khabieh/Reuters)

A Syrian refugee man (obscured) moves boxes of goods at his shop in Zaatari refugee camp near the border with Syria, in Mafraq, Jordan October 15, 2016. (Photo by Ammar Awad/Reuters)