Police and a bomb disposal unit were called to a north Northumberland village yesterday after a mortar shell was found.
The A1 was closed briefly while the Second World War device was detontated safely in Warenford.
A police spokesman said: “At 4.20pm yesterday, police received a report that a member of the public had found an object that appeared to be a Second World War bombshell by the river bank in Warenford.
“Officers cordoned off an area around the find as a precaution and experts from the bomb disposal unit attended.
“A section of the A1 was closed for around five minutes to allow for the device, which was later confirmed as a Second World War mortar round, to be safely detonated.
“The police cordon was stood down at 9.35pm.”