Anti-Bolshevik League incident
The Anti-Bolshevik League incident, or AB League Incident (AB tuan shijian, AB 团事件), was a period of political purge in the territory of a Chinese Communist revolutionary base in Jiangxi province. Mao Zedong accused his political rivals of belonging to the Kuomintang intelligence agency "Anti-Bolshevik League".
Source: Wikipedia — Anti-Bolshevik League incident (CC BY-SA 4.0)