The British Army has denied claims that its helicopters crossed the border into the Republic without clearance.
Sinn Fein councillor Mr Arthur Morgan called the alleged incursion into Co Louth a disgrace and demanded that Taoiseach Bertie Ahern should raise the issue with Britain.
But an Army spokesman says the claims are ridiculous - especially on a day when officers had saved lives by defusing a 130lb bomb in the province.
Mr Morgan said local people contacted him at 9.30 a.m. reporting that helicopters had entered the Hackballcross area.
"It is unacceptable that the British Army continues to patrol nationalist areas of the six-counties. To cross the border is simply a disgrace," the Louth councillor said.
"The Minister for Foreign Affairs and the Taoiseach must let the British Government know that this is unacceptable."
The Army spokesman said: "While there were routine helicopter patrols active north of the border in South Armagh this morning, no border incursion took place.
"It is ridiculous to hear such allegations on the same day the army made safe a 130lb bomb at Sixmilecross in Co Tyrone.
PA