 Upon creation , the 766th Unit was designed to vary in size , consisting of a number of smaller units capable of acting alone . Eventually , it was reinforced to the size of a full regiment , with 3 @,@ 000 men equally distributed across six battalions ( numbered 1st through 6th ) . It was made directly subordinate to the KPA Army headquarters and put under the command of Senior Colonel Oh Jin <unk> , who would command the unit for its entire existence . All 500 men of the 3rd Battalion were lost just before the war started when their transport was sunk while attacking Pusan harbor by the Republic of Korea Navy . For the remainder of its existence the regiment was <unk> down by losses until it numbered no more than 1 @,@ 500 men and could not muster more than three battalions . 
