A "suspicious device" found by charity shop workers in a book caused the evacuation of about 30 buildings.
Police cleared parts of Mill Street in Bideford, Devon, at about 14:20 BST and set up a 100m (328ft) cordon.
The cordon was lifted by 18:20, officers said, and the object was destroyed by a bomb disposal team.
Devon and Cornwall Police said it was called to reports of a suspicious device found within a donation bag.
Sup Toby Davies said: "The device was not dangerous and no member of the public was put at risk.
"Plans were put in place as a precaution and the residents were returned home as soon as possible."