Police are still working to establish whether a device blown up by bomb disposal experts was dangerous or not.
An area of Holywell in Watford was cordoned off for around six hours after a suspicious device was found in a parked car. Police have described the device as “small and round”.
The bomb squad carried out a controlled explosion in King George V Recreation Ground at around 5.30pm.
Officers had initially been called to Charlock Way just before midday before a bomb disposal unit arrived and the surrounding area was cordoned off.
The bomb disposal unit in Caractacus Green yesterday afternoon
Homes close to the scene were evacuated while other neighbours were told to stay inside.
A police presence remained in the area this morning and enquiries are ongoing.
County councillor for west Watford Nigel Bell praised residents for the "patience" they showed while the incident was ongoing, particularly those living in Charlock Way and Caractacus Green.
A police spokeswoman confirmed: "Police were called at 11.51am yesterday (Wednesday) to Charlock Way, Watford, to reports of a suspicious device that had been found inside a parked car.
"Officers attended, a cordon was put in place and some homes were evacuated.
"A specialist team from the Explosive Ordnance Disposal (EOD) team also attended and carried out a controlled explosion of the object on a field off The Roundway in Watford .
"Enquiries are on-going and officers are working to establish exactly what the device was."
Read more: Controlled explosion carried out after 'grenade thrown into car'
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