A man reacts over dead bodies prior to burial in a graveyard after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria, October 24, 2016. (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)

Akram Abu al-Foz places a painted empty shell on top of a Christmas tree he decorated from empty shells he collected in the rebel held besieged city of Douma, in the eastern Damascus suburb of Ghouta, Syria December 23, 2016. (Photo by Bassam Khabieh/Reuters)

Guests brew coffee during a wedding ceremony for a Free Syrian Army fighter in the town of Douma, eastern Ghouta in Damascus, Syria January 19, 2016. (Photo by Bassam Khabieh/Reuters)

A fighter belonging to Jaish al-Islam (Islam Army) runs to take cover near the frontline on March 14, 2016 in the neighbourhood of Jobar, on the eastern outskirts of the capital Damascus. (Photo by Amer Almohibany/AFP Photo)

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 man gets stuck under debris at a damaged site after an airstrike in the Saqba area, in the eastern Damascus suburb of Ghouta, Syria, January 9, 2018. (Photo by Bassam Khabieh/Reuters)

Syrian President Bashar Al Assad watches as Pope John Paul II boards his plane at Damascus airport May 8, 2001 at the end of the Pontiff's four-day visit to Syria.