On May 30, Biafra Day, the red, black and green flags with their unmistakable yellow half-sun had been stuck out of tiny second- and third-floor windows of the sad old buildings that overlook the crumbling roads leading to Ezukwu Market in Aba.

The day before, a rumour was doing the rounds that the markets would be closed – that there would be trouble. Last year, youths had marched in Enugu, once capital of the short-lived Republic of Biafra. The police had been called in. There had been a riot.