[VOA] Nairobi -- UNHCR, the United Nations refugee agency, as well as UNICEF and the Norwegian Refugee Council, said this week that more than 13,200 schools in eight African nations have had to close because of insecurity, affecting the education of at least 2.5 million children. According to the agencies' data on school closures over the last four years, the number of schools closed in the Sahel region has grown more than fivefold, from 1,700 to 9,000, with Burkina Faso accounting for two-third of the closures.