A 37-year-old man has been arrested on suspicion of making explosives.
Cambridgeshire Police closed New Road in Woodston, Peterborough on Saturday afternoon to investigate reports of a suspicious package inside a house.
Residents were evacuated from nearby homes and the RAF Bomb Disposal Squadron was called.
Police thanked local chip shops and Belsize Community Library volunteers for offering people food and shelter. The road reopened at about midnight.
A police spokeswoman said: "We are treating this as an isolated incident and do not believe there to be an ongoing risk."
The man from Peterborough remains in custody.