In April 1944, the Chinese Expeditionary Force launched a counteroffensive in Yunnan. The key element of the plan was a coordinated attack by two armies, against the northern and southern sections of the Yunnan-Burma Road. The objective of the attack in the north was to occupy Tengchong; in the south, it was to capture Mount Songshan, and from there move on the strategically important town of Longling. In the summer of 1944, under the command of General Song Xilian, a detachment from the left wing of the Chinese Expeditionary Force laid siege to Mount Songshan. Meanwhile, the main force advanced on Longling.