What was the biggest riot recorded in history?

I don't know if it is the biggest,but it is definitely one of the worst riots of all time.The 2008 Greek riots,which started on December 6, when Alexandros Grigoropoulos (Αλέξανδρος Γρηγορόπουλος), a 15-year-old student, was fatally shot by a police officer,Epaminondas Korkoneas