The device was found last week in the Rivenwood area of Newtownards.

Following the discovery of the suspected munitions on Thursday morning at around 11 a.m., a significant number of homes were evacuated.

Superintendent Johnston McDowell, the PSNI’s District Commander for Ards and North Down, explained on Monday that due to the size of the bomb, a 400-metre (1,312ft) safety cordon has been established.

He emphasized that there is a serious risk of death or injury to anyone within the cordoned area.

The operation has entered the mitigation phase, allowing the military to examine the device. A decision will be made later regarding whether the bomb will be dealt with on-site or removed, he added.

McDowell noted that based on similar past operations, it is expected that the procedure will take approximately five days, though it could be shorter or longer.

“More than 400 homes have been affected by this operation, which is a significant number of properties,” he stated.

“I, along with our partners, want to thank residents for their patience and understanding. If police have not contacted you directly, it is unlikely that your home will be impacted by the clearance operation at this time.”

He added, “The operation has now entered the mitigation phase, and efforts are underway to establish protection for nearby properties.”

“There is no definitive timeline, but similar operations in the past have typically taken around five days to ensure the area is safe to re-enter. A police cordon remains in place, and road users are advised to avoid the area.”

McDowell acknowledged the frustration and disruption caused by the operation, but stressed that public safety is the top priority and that no risks will be taken.

He also mentioned that a multi-agency support hub, including the local health service Trust, has been set up to assist residents with vulnerabilities in finding more suitable accommodation.