 Soon afterwards, the KMT division was ordered to assist the Thai government to counter the advancing armies on Thailand's northern borders and the internal threat from the Communist Party of Thailand.Fierce battles were fought in the mountains of Doi Laung, Doi Yaw, Doi Phamon, and Mae Aabb, and the communist uprising was successfully countered.The bloodiest operation was launched on 10 December 1970, a five-year-long campaign that claimed over lives, many from landmines.