Bomb experts are continuing to examine a suspicious device after it was first discovered in Co Fermanagh on Tuesday.
It was found at the Clogh Road area of Rosslea at around 11pm. Locals have described it as a 'beer keg' type device.
Police said they received a report that a device had been left in the area before army bomb teams arrived on the scene.
District Commander Chief Superintendent Pauline Shields said the operation would continue this afternoon.
"I recognise the inconvenience this may cause to local residents however my priority is to ensure the safety of the local community and to protect everyone," she said.
"Can I thank the public for their continued patience and understanding."
The Clogh Road remains closed to traffic and diversions are in place. Motorists are asked to avoid the area and seek an alternative route where possible.
The latest security alert comes after an off-duty police officer spotted a 60kg device in an abandoned Silver Volkswagen Bora car in the Derrylin Road area of Fermanagh on Friday evening.
Police had said that Lisnaskea Station was the target, but in a statement to UTV, Óglaigh na hÉireann (ONH) said the bomb was set for the Lough Erne golf resort.
The world's most powerful leaders are expected at Lough Erne for the G8 summit in three months' time.
The potentially deadly device was found just 16 miles from the hotel that will host the summit.