enemy hands. In order to reinforce Yanzhou, the nationalist Reorganized 25th Division stationed in northern Jiangsu was sent from Xuzhou along the Tianjin-Pukou Railway, and its advanced guard had reached the region of Jie River () north of Tengzhou by June 28, 1948. The communists decided to ambush the nationalist reinforcement by deploying the 9th Column and the 13th Column, while the communist 7th Column was ordered to stop its assault on Yanzhou (兖州) and redeployed to assist the 9th and the 13th Columns. As the communists laid their trap, the nationalists changed their priority. The nationalist forces in Sui (睢) County and Qi (杞) County in eastern Henan, under the command of the corps commander Qu Shounian (区寿年), were besieged by the enemy and the situation was far more desperate than Yanzhou, so the nationalist Reorganized 25th Division was redeployed to Shangqiu by rail to reinforce the battlefield in eastern Henan, and thus inadvertently avoided the ambush set up for them. The nationalist redeployment had left a strategically important town, Yanzhou, dangerously undermanned: the nationalist garrison of the town only had the Reorganized 12th Army and security divisions totaling 28,000 troops. The nationalists were betting on several factors that favored the defenders securing the city: As an important junction of the Tianjin-Pukou Railway, nationalist reinforcement from other places could readily reach the town via railroad. Being located on the western bank of the Si (泗) River, the area surrounding the town was wide open with little cover for would-be attackers. Furthermore, there were semi-permanent fortifications both inside and outside the town. The battle and the consequent fall of the town into the enemy hands proved that these advantages could not be counted on. The communists decided to attack Yanzhou (兖州) again by concentrating a total of fifteen brigades from the Shandong Corps and local units to take the town and annihilate nationalist reinforcement. The communist 7th Column, 13th Column and units from Central Shandong Military District were tasked to attack the town, while the communist 9th Column was deployed to the north of Yanzhou, and communist units from southern Shandong Military District were deployed to the south of Yanzhou to ambush nationalist reinforcements. The communist Bohai Column was deployed to the east of Jinan to prevent nationalists stationed in the city from reinforcing Yanzhou. Second stage On July 1, 1948, the communist Shandong Corps besieged Yanzhou again. The communist