Homes in London Colney were evacuated yesterday and then again today after explosive shells were found in a garden.
Floral Drive was cordoned off at 2.55pm yesterday after Hertfordshire police were called by a member of the public, who reported finding an artillery shell in their garden.
Both police and bomb disposal officers attended the property, and it is believed something was taken away and a controlled explosion took place.
Homes nearby were evacuated until 6pm.
The second call came at 10.02am today to the same location. A member of the public reported finding more shells.
A cordon was put in place again, and some homes were evacuated. People were back in their homes by 1pm.