The situation came to a head in late 1940 and early 1941 when clashes between Communist and KMT forces intensified

The situation came to a head in late 1940 and early 1941 when clashes between Communist and KMT forces intensified. Chiang demanded in December 1940 that the CPC's New Fourth Army evacuate Anhui and Jiangsu Provinces, due to its provocation and harassment of KMT forces in this area. Under intense pressure, the New Fourth Army commanders complied. The following year they were ambushed by KMT forces during their evacuation, which led to several thousand deaths.