They were called civilian workers on base. The vetting process left something to be desired. One day, we reported several of the trash pickup people measuring the distance from the road to the barracks. It seems they were pacing the distance off and writing it down. Not long after that the civilians disappeared for a month or two. Couldn't trust young Vietnamese men, never understood why they were not in the RVN, (figured out they were young VC). Oh the fun we had.