At one point, the French Battalion was forced to fend off several KPA counterattacks with bayonet charges after running out of ammunition. The French Battalion's action at Wonju impressed Ridgway, who later encouraged all American units in Korea to utilize bayonets in battle. The KPA tried to encircle the attacking UN forces as the latter began to gain the upper hand, however artillery fire broke up the KPA formations, and they had suffered an estimated 2,000 casualties in the aftermath of the battle. When air support returned on January 11, the attacking UN forces inflicted another 1,100 KPA casualties and captured Hill 247 by January 12. Although the cold weather and the stubborn KPA defenses prevented the UN forces from entering Wonju, the capture of Hill 247 had put all of Wonju within UN artillery range, and the village soon became a no man's land under the devastating bombardment. Although the capture of Hill 247 had forced KPA V Corps to abandon Wonju with heavy losses on January 17, KPA II Corps' infiltration in the UN rear area had become so serious that it threatened to outflank the entire UN front and force a complete evacuation of Korea by mid-January. With the bulk of US X Corps tied up to the south of Wonju while ROK III Corps was in disarray, the front between Wonju and the east coast was undefended, and about 16,000 KPA soldiers entered the gap while establishing guerrilla bases from Tanyang to Andong. The battles along the central front soon degenerated into irregular warfare between company-sized UN patrols and KPA guerrilla bands. In an effort to stabilize the front, Ridgway ordered the US 2nd Infantry Division to withdraw from Wonju while pulling the central and eastern fronts back to the area between Wonju and Samch'ok, and this resulted in another retreat. Ridgway also sent the US 187th Regimental Combat Team, the US 5th Cavalry Regiment, the US 1st Marine Division and the Greek Battalion to contain KPA guerrillas east of Route 29 and north of Andong and Yeongdeok. About 30,000 American infantry were deployed to the central front by mid-January, and the KPA guerrillas were blocked in a narrow salient along the hills at the east of Route 29. To eliminate the KPA threat in the UN rear, Almond ordered all X Corps units on Route 29 to launch aggressive patrols to destroy the KPA supply bases and guerrilla bands. Specially trained irregular forces, such as X Corps' Special Action Group, also hunted KPA units by operating as guerrillas themselves.