 UN forces responded to the threat with overwhelming numbers . A large force of South Korean troops , designated Task Force P 'ohang , was massed and sent into P 'ohang @-@ dong to engage the 766th Regiment and the 5th Division . ROK troops attacked toward An <unk> @-@ <unk> to the east , forcing the KPA 's 12th Division into a full retreat . Threatened with <unk> , the KPA 's 5th Division and 766th Regiment were ordered into full retreat on August 17 . By this time , the 766th had been reduced to 1 @,@ 500 men , half its original strength . 
