The Division’s war of maneuver had worked well in halting this round of the CCF offensive, but the Communists were far from finished. As 17 enemy divisions were still available to attack, the Marine division was shifted to the east on 1 May in preparation for an expected battle. On the 16th of May the Chinese offensive again opened, with the enemy hitting more to the east than had been expected, and making a deep but narrow penetration near the coast. The Marines moved eastward, established blocking positions, and engaged fringe units of the drive. This allowed the right flank Army division to move farther east and brake the enemy’s rush. The enemy was dangerously overextended when the UN counterstroke hit him late in May. For a month the Eighth Army attacked and advanced, the Marines slugging ahead day after day in the X Corps zone of action. CCF casualties mounted high, and Marine veterans of only a few months of Korean service saw scores of enemy corpses left behind on the battlefield as the enemy withdrew northward. This great UN counteroffensive netted prisoners all along the EUSAK front as remnants of CCF platoons and even companies threw down their arms. Marines captured their share. Upwards of 10,000 Chinese surrendered to the Allies in a 10-day period--more prisoners than had been taken up to this time. As the Chinese withdrew northward they left determined NKPA troops behind. The 1st Marine Division moved slowly forward, fighting for every inch of ground. So fierce was the enemy’s resistance that at times during June the division commander was forced to commit all four regiments (the KMCs included) in the attack at the same time in order to seize designated objectives. This was a modification of accepted tactical doctrine, necessitated by the situation. Throughout March, April, and part of May, Marine pilots continued to provide close air support not only for the 1st Marine Division, but also for other Allied units as directed by JOC. From the beginning of Operation STRANGLE on 20 May this interdiction effort had first priority, and close air support to all infantry units was secondary. Difficulties in air-ground communication continued as radio frequencies were heavily burdened with traffic. Although the 1st Marine Division received a proportionate share of the few air support missions flown, the frustrating time lag between requests for air support and the arrival of planes on target continued into the next year. Some planes were always available for front line support, although rarely ever enough according to infantrymen’s opinion. When they had the chance, 1st MAW pilots viciously attacked the fleeing enemy to ease the way for advancing ground troops. During June the unrelenting pressure of combined air-ground attacks sometimes caused large groups of enemy to surrender. Marines also captured thousands of rounds of enemy ammunition and other equipment.