The woman - Nanki Devi of Maithi Saidullaganj village - had gone to her fields where the incident happened.
The locals heard a loud cry but before they could rush to her rescue, the tiger dragged her into the forest, the police said.
Later a half-bitten body of the woman was recovered, they added.
Following the incident, the family of the deceased and other locals lodged a strong protest against forest department staff alleging that their repeated complaints about maneaters being active in the region had been ignored.