LEBANON, Tenn. — A man with a metal detector made an explosive discovery when he found a live mortar from World War II Monday.

Police said the munition was a remnant from when the area was used as a training ground during the war.

The bomb squad determined the mortar was too unstable to be moved so it was detonated near where it was found.

“The blast was heard from a distance, which caused alarm for many residents,” Lebanon police said on social media. “We appreciate everyone’s concerns and phone calls.”

Authorities searched the area for more mortars before deeming it safe.