(Reuters) – Thousands of children in Central African Republic are being prevented from starting the academic year by armed groups which are occupying schools and installing barriers nearby, the United Nations said on Wednesday. Children across the country returned to class last week, but insecurity in some areas outside the capital Bangui has disrupted the start of the school year and stopped 10,000 pupils from resuming their education, according to the U.N. children’s fund (UNICEF).