A man prepares plastic strings, used to produce mats, inside a mat factory in the rebel-controlled area of Maarshureen town in Idlib province, Syria, December 22, 2015. The town is known for the significant number of mat factories which exports its production mainly to nearby Iraq through checkpoints controlled by insurgents. But in the past months the business has declined due to heavy airstrikes against insurgents, vendors said. (Photo by Khalil Ashawi/Reuters)

A Free Syrian Army (FSA) fighter reacts as he mourns near the body of his brother, who was an FSA fighter and died during an offensive against Islamic State fighters to take control of Qabasin town, on the outskirts of the northern Syrian town of al-Bab, Syria January 10, 2017. (Photo by Khalil Ashawi/Reuters)

Mariam, a 9-year-old girl, carries her brother as she stands with other children at an underground ancient cemetery in Jabal al-Zawiya in the southern countryside of Idlib November 26, 2014. Residents are using ancient caves and cemeteries as underground shelters to hide in during shelling from forces loyal to President Bashar al-Assad. Picture taken November 26, 2014. (Photo by Khalil Ashawi/Reuters)

In this Friday, January 24, 2014 photo, Afghan refugee girl, Robina Haseeb, 5, poses for a picture, while playing with other children in a slum on the outskirts of Islamabad, Pakistan. (Photo by Muhammed Muheisen/AP Photo)

Weakened by sickness and malnutrition, Arbty Mohammad, 2, lies in the Banadir Hospital on August 12, 2011 in Mogadishu, Somalia. Some 100,000 Somalis have flooded into Mogadishu from drought and famine stricken areas of the country. The UN warned Friday that a cholera epidemic could spread through Mogadishu, as Somalis fill unsanitary makeshift camps throughout the capital. (Photo by John Moore/Getty Images)

Christian families living in a refugee camp stand under a tree in Kaga-Bandoro, Central African Republic, Tuesday February 16, 2016. Refugees in the north of Central African Republic say they hope the new president will bring peace but no one is heading home just yet. Thousands are still living in displacement camps in Kaga-Bandoro, a stronghold of the former Muslim rebel group known as Seleka that was in power for nearly a year. The one-time rebels say they are waiting to see how the election turns out before taking any action. (Photo by Jerome Delay/AP Photo)

A man carries an injured woman in a site hit by what activists said were airstrikes carried out by the Russian air force in the rebel-controlled area of Maaret al-Numan town in Idlib province, Syria January 9, 2016. At least 70 people died in what activists said where four vacuum bombs dropped by the Russian air force in the town of Maaret al-Numan; other air strikes where also carried out in the towns of Saraqib, Khan Sheikhoun and Maar Dabseh, in Idlib. (Photo by Khalil Ashawi/Reuters)

Damaged buildings stand in the rebel-controlled area of Maaret al-Numan in Idlib province, Syria September 6, 2016. (Photo by Ammar Abdullah/Reuters)