The intense level of activity by the Royal Ulster Constabulary and the Army over the incident on Saturday night, in which no one was hurt, reflects the concern that an IRA sniper team is at work along the border.
Six members of the security forces have been killed in single-shot attacks in the border area over the past year, five in the area of south Armagh known as 'bandit country', and the other in south Fermanagh.
It emerged at the weekend that Lt- Gen Sir Roger Wheeler, General Officer Commanding Northern Ireland, sees the sniping threat as a major challenge, and has made it a priority to catch the IRA team. When the latest attack occurred, at 10pm, the soldiers were stopping cars on the Newry Road, near Newtownhamilton, Co Armagh. They returned fire.
The incident happened near the spot where Pte John Randall, of the 1st Battalion, Duke of Edinburgh's Royal Regiment, was killed by a single shot on 26 June as John Major visited the province.
Police and army patrols are regularly fired on without injury in the ghettos around Belfast and Londonderry, but the fear is that a sniping team has been trained and is using the Barrat 'Light Fifty' Rifle, among other weapons. The 0.5in calibre weapon, 5ft long and weighing more than 30lbs, has a range of more than a mile and is capable of piercing body armour with bullets that leave the muzzle at 1,907mph.
A man who was nearby on 17 July, when the last victim, L/Cpl Kevin Pullin, also of the Duke of Edinburgh's Regiment, was killed, is convinced that a high-powered weapon was used. He said the bang was so loud many thought a bomb had exploded. The same witness heard the shot that killed Police Constable Jonathan Reid on 25 February, 1993, one of three to die in Crossmaglen, and said it was fired from a different weapon, probably an AK-47.
One close observer of the scene in south Armagh said the IRA's change of tactics to sniping is a response to the army's decision to build high watch-towers which overlook most of the hilly countryside and make it difficult for the terrorists to use bombs with command wires to attack patrols.
The apparent success of the switch in tactics and the security forces' determination to catch the team was reflected in the aftermath of the last attack, he said.
'The soldiers were very, very scared. Really nervous. When an attack happens they don't know where the shot has come from. That was the second soldier from the same battalion to die.'