A British soldier opened fire during an incident at a border checkpoint in south Armagh at the weekend.
A soldier manning a joint military and police checkpoint just over half a mile south of Crossmaglen fired two shots in the early hours of Saturday morning.
There were no injuries or arrests in the incident, which is thought to have involved a speeding car.
A British military spokesman said the soldier responsible had not been suspended, and suggested the shots were fired in self-defence.
He said: “The rules of engagement hinge upon the threat to one’s own life or someone else’s.”
Asked about the nature of the perceived threat was, the spokesman added: “I think the police and ourselves would be concerned at any breach of a vehicle checkpoint or anyone not respecting the validity of a checkpoint in trying to maintain law and order.”
Three weeks ago, two cars drove through checkpoints during a road safety operation in Crossmaglen.
Sinn Féin assembly member Conor Murphy said the latest incident underlined his party’s case that the British army should leave south Armagh.
“They are not wanted in south Armagh and should be withdrawn immediately,” he said.
“Indications would suggest this was some sort of road traffic incident and yet the British army respond by firing live rounds. It is completely unacceptable.”
Mr Murphy questioned whether allegations that cars were driving at speed through checkpoints in the South Armagh area were correct.
“At a time when Sinn Féin have placed the issue of British army demilitarisation at the heart of the political agenda many local people are questioning the validity of reports, all of which emanate from the British Army or PSNI press operations, about a number of cars breaking through checkpoints in the Crossmaglen area,” he said.
There had been more of these incidents reported in the last three months than in the previous 10 years,” he pointed out.
“There is a feeling locally that many of these stories about British soldiers diving into hedges or receiving injuries from passing cars are fantasy and part of a very clear agenda to justify the continuing presence of the British military in south Armagh,” he added.
A British army press officer described Mr Murpy’s comments as “flippant”.
“I sincerely hope these suggestions are not representative of the views of a political party claiming to hold a democratic mandate in a society where law and order will prevail,” he said.
“Police and soldiers have been perilously close to serious injury or worse as a result of dangerous driving by individuals bent on avoiding - for whatever reason - vehicle checkpoints.”
Mr Murphy said he had hit a “raw nerve” with the British Army.
The British Army did not represent anyone in Ireland, he added.
“They are an occupying force who continue to terrorise nationalist communities across the six counties. British Army checkpoints in South Armagh are nothing to do with the rule of law. Like their fortresses and helicopter flights they are about domination, intimidation and terror.
“The British Army may have a desire to continue occupying South Armagh and other republican heartland’s, they may have a desire to continue firing live rounds at local civilians but Sinn Féin will continue to demand that the British government honour their commitments and remove their war apparatus and their personnel from our communities.”