Indigenous Sahrawi girls play on an improvised see-saw at a refugee camp of Boudjdour in Tindouf, southern Algeria March 3, 2016. UN Secretary General Ban Ki-moon is scheduled to visit the Sahrawi refugees in south-west Algeria's Tindouf region. (Photo by Zohra Bensemra/Reuters)

A boy looks for scrap metal using an improvised magnetic tool near a construction site in New Delhi, India, March 21, 2016. (Photo by Cathal McNaughton/Reuters)

A girl carries on her head a pile of dried shrubs she gathered for cooking and heating, in Kabul, Afghanistan November 18, 2015. (Photo by Omar Sobhani/Reuters)

Boys pan for gold on a riverside at Iga Barriere, 25 km (15 miles) from Bunia, in the resource-rich Ituri region of eastern Congo February 16, 2009. Ituri is one of many areas of the country to have experienced bitter ethnic conflict between rival tribes in recent years. Massacres have left tens of thousands dead. It is this fighting that led U.S. authorities to take the unprecedented step of naming Congo in section 1502 of the Dodd-Frank financial regulation act, which says U.S.-listed companies that source gold, tungsten, tantalum and tin from Congo or its neighbours must assure the U.S. stock exchange regulator that their business is not helping fund conflict. (Photo by Finbarr O'Reilly/Reuters)

A Syrian refugee girl plays outside a tent at a refugee camp in Zahle in the Bekaa valley November 18, 2014. In October, Lebanon, which has the highest per capita concentration of refugees in the world at one in four residents, said it could not cope with more than one million Syrians and has asked for funds to help look after them. (Photo by Mohamed Azakir/Reuters)

Syrian refugees covered with dust arrive at the Trabeel border, after crossing into Jordanian territory with their families, near the northeastern Jordanian border with Syria, and Iraq, near the town of Ruwaished, east of Amman September 10, 2015. (Photo by Muhammad Hamed/Reuters)

Eritrean refugee children play at Mai-Aini refugee camp near the Eritrean boarder in the Tigrai region in Ethiopia February 10, 2016. Each month as many as 5,000 people flee Eritrea according to U.N. figures, estimates the Eritrean government disputes. The government puts the population at about 3.6 million, while other estimates suggest it could be almost double that. (Photo by Tiksa Negeri/Reuters)

Internally displaced people who fled flooding of the overflowed Shabelle river rest after receiving relief assistance near Baledweyne town in central Somalia, June 22, 2016. (Photo by Feisal Omar/Reuters)