Police have closed part of Trowbridge Road in Bratton, reportedly because a grenade has been found.
The road has been closed in both directions between the Capps Lane junction and the Lower Road junction.
Police are at the scene, with explosive experts from the MOD curently en-route to assess the situation.
Chief inspector Charlie Dibble said: "We have discovered an old grenade which has been dug up in a field, and we are dealing with it in a controlled way.
"We don't know if it's live. It's very old and very rusty, and the location of it is near old military bases so it could be a practice one, or it could be a live one, but either way our colleagues in the military will deal with it."