Officers were called to the area of West Poplar and South Cottage around 8 p.m. Saturday night. They found 22-year-old Michael Harris walking down the street carrying, what appeared to be, a hand grenade.
Officers ordered Harris to put the device down and arrested him.
Bomb squad members from the Visalia Police Department and Tulare County Sheriff's Department were then called in to detonate the device.
Harris is facing charges including possession of an explosive device and manufacturing an explosive device.