"Tsuwamono" were military force not specified in the ritsuryo system (a system of centralized government based on the ritsuryo code), and they were a kind of mercenary troops that were utilized to suppress civil disorder incidents which frequently occurred in the provinces.
「兵(つわもの)」は、律令制には規定されていない軍事力で、地方で頻発する騒擾事件の鎮圧の為に用いられた一種の傭兵団。