A hand grenade packed in a box was delivered to the manager of Axis Bank located at Moreh Ward No VI by a miscreant at around 10.30 am on Thursday.
An unidentified man brought the package at the bank and asked an employee to give it to the manager before leaving, sources said.
On discovering that the package contained a hand grenade, the manager immediately informed the Police, after which it was collected for disposal.
A warning letter bearing the name of a valley based proscribed group was also found inside the box, the sources added.