The Atlantic City bomb squad was dispatched to a southern New Jersey home over the weekend after a man dug up a live cannonball in his backyard.
Police said the Lower Township man was digging behind his West Bates Avenue home when he discovered the explosive Saturday.
The brass-capped cannonball was approximately 5 inches in circumference and was stamped "4k, 85mm," according to police.
The bomb squad took an x-ray of the device and determined it was fully functional, officials said. The cannonball was later detonated in an unpopulated area.
Police said the discovery is not unusual for this part of the state, but residents are advised to never touch or move any found artillery shells.
Originally fired as solid projectiles, cannonballs developed over time to include fuses and explosive materials.
Earlier this year, a rusty cannonball was found in a backyard in Madison, New Jersey.