A Russian Sukhoi Su-25 fighter jet takes off during the withdrawal of Russian troops from Syria at Hmeymim airbase, Syria, March 16, 2016. (Photo by Vadim Grishankin/Reuters/Russian Ministry of Defence)

A female Syrian soldier from the Republican Guard commando battalion drives a tank during clashes with rebels in the restive Jobar area, in eastern Damascus, on March 25, 2015. The female battalion, which was created nearly a year ago, consists of 800 female soldiers who are positioned in the suburbs of the Syrian capital where they monitor and secure the frontlines with snipers, rockets and machine guns. (Photo by Joseph Eid/AFP Photo)

A participant covered in coloured powder gestures as she stands near a Syrian army soldier during “I Love Damascus” marathon at Umayyad Square in Damascus, Syria October 7, 2016. (Photo by Omar Sanadiki/Reuters)

A girl wearing a butterfly headband poses for a picture near damaged buildings in the rebel held besieged city of Douma, in the eastern Damascus suburb of Ghouta, Syria January 19, 2017. (Photo by Bassam Khabieh/Reuters)

A young Free Syrian Army fighter holds a rifle in Haresta neighbourhood of Damascus January 16, 2013. (Photo by Goran Tomasevic/Reuters)

A Libyan rebel fires on a government jet as a natural gas facility burns on the frontline on March 9, 2011 near Ras Lanuf, Libya. The rebels pushed back government troops loyal to Libyan leader Muammar Gaddafi towards Ben Jawat.

Libyan rebel fighters protect a pro-Gaddafi loyalist fighter from angry onlookers as he is brought in for medical attention to the Tripoli Central Hospital on August 25, 2011 in Tripoli, Libya. Heavy fighting continues in the Libyan capital between Gaddafi's forces and the surging rebel presence. Rebels, who have issued a $1.7m reward for Gaddafi's capture “dead or alive”, are attempting to reach Colonel Gaddafi's hometown of Sirte but have met loyalist resistance. (Photo by Daniel Berehulak/Getty Images)

Girls sit inside an empty classroom as they pose for a photograph during a celebration marking the end of the school year in the town of Douma, eastern Ghouta in Damascus, Syria May 21, 2016. (Photo by Bassam Khabieh/Reuters)