A controlled explosion was carried out at a film studio when builders stumbled across an unexploded bomb.
Bomb disposal experts were called to Elstree Studios in Shenley Road in Borehamwood this morning after workers removing the Mound discovered the device.
Hertfordshire Police were called at 10.15am and a 100 metre cordon was put in place around the four acre site.
The device was later detonated at 1.30pm.
It is not known whether the bomb was a weapon or a prop from one of the films made at the studio.