(UNICEF) – As children around the world return to school, there are more than two million in Syria who will not be able to join them. According to UNICEF, another 400,000 are at risk of dropping out as a result of conflict, violence and displacement. As the conflict in Syria enters its fifth year, the crisis continues to wipe out years of achievements in education. Some children in Syria have never been inside a classroom, while others lost up to four years of their schooling. There are 5,000 schools across the country that cannot be used because they have been destroyed, damaged, converted into shelters for displaced families or have become bases for armed forces and groups. Many parents worry about sending their children to school because of the dangers on the road to or at school itself. In 2014 alone, at least 60 schools were attacked, sometimes deliberately. Syria’s teachers have also paid a heavy price, with more than a quarter of the teaching workforce leaving posts.