They involved battles between Uighurs, the Turkic-speaking, predominantly Muslim group indigenous to Xinjiang, and ethnic-Han Chinese who make up more than 90% of China’s population.
Of more than 200 people who were killed on the first day of the violence in Erdaoqiao and other areas of Urumqi, many were Han.
In other parts of the city, the residents are mainly Han people, who make up three-quarters of Urumqi’s population and dominate its economy.
Among such people, Mr Chen may have enjoyed some support for his gulag-building project, although official documents leaked to the New York Times last year suggested that some local officials resented his clampdown.
With his gulag, Mr Chen has ensured that ethnic conflict in Xinjiang will haunt China long into the future.