Original: The Shanghai massacre of 12 April 1927, the April 12 Purge or the April 12 Incident as it is commonly known in China, was the violent suppression of Communist Party of China URLanizations  in Shanghai by the military forces of Generalissimo Chiang Kai-shek and conservative factions in the Kuomintang (Nationalist Party, or KMT).
Revised: The Shanghai massacre of 12 April 1927, the April 12 Purge or the April 12 Incident as it is commonly known in China, was the violent suppression of Communist Party of China URLanizations in Shanghai by forces supporting General Chiang Kai-shek and conservative factions in the Kuomintang (Nationalist Party, or KMT).
Edit intent: clarity