Cairo - A lawyer says an Egyptian court has ordered the detention of 24 Nubians for 15 days pending investigation for participating in a protest earlier this month. Nubians are an ethnic minority.Moustafa el-Hassan says Wednesday's decision comes after prosecutors appealed an earlier decision to release them on bail. Their release, which was ordered on Tuesday, had not been finalised.They were arrested after setting out on a march in the southern city of Aswan to demand their right to return to their ancestral land around the lake formed by the Aswan High Dam. Charges include illegal protest, receiving funds from foreign sources and blocking public roads.Nubians trace their roots back to an ancient civilisation on the Nile. They have been forcibly displaced four times in the last century.