Colonel Idi Amin took power in Uganda following a coup in January 1971. At the time Nasur was serving as the chief sports officer and sports trainer at Kasijjagirwa Barracks in Masaka. That year he was promoted to the rank of second lieutenant. After completing a series of short courses, he was attached to the Ministry of Education and given charge of gymnastics training. In 1974 Amin promoted him to the rank of captain and made him the army's top sports officer. Nasur held this position until Amin appointed him Governor of Central Province on 8 January 1975. That year he was promoted to the rank of lieutenant colonel. Shortly after taking office he replaced the head of the Federation of Uganda Football Associations, despite having no legal authority to do so. He then declared himself disciplinary officer of the Uganda national football team and instituted a team code of conduct. In April he created a committee for sports discipline in Central Province and appointed himself its chairman. Amin also placed Nasur in charge of the Economic Crimes Tribunal, which was tasked with combatting smuggling and economic malpractice. According to Peter F. B. Nayenga, it was also "common knowledge" that Nasur was "personally responsible for many of the deaths" that occurred around Kampala and Entebbe.