Empty mortar shells sparked a police operation at the Courier Post depot in Wellington this afternoon.
Police were called to the scene on Kaiwharawhara Rd after an "item of concern" was found at the depot, a spokeswoman said.
"It turns out that they're likely empty mortar shells," she said.
The shells were being sent in the mail. Police have spoken to the intended recipient.
The road was closed and a cordon had been put in place, but this has since been lifted.
Courier Post has been contacted for comment.