Syrian refugee students raise their hands as they attend class in a UNICEF school at the Al Zaatari refugee camp in the Jordanian city of Mafraq, near the border with Syria March 11, 2015. Nearly four million people have fled Syria since 2011, when anti-government protests turned into a violent civil war. Jordan says it is sheltering around 1.3 million refugees. REUTERS/Muhammad Hamed (JORDAN - Tags: CIVIL UNREST CONFLICT SOCIETY IMMIGRATION EDUCATION)