The Defence Forces has confirmed that shots were fired at Renmore Barracks during a stabbing incident last night.
An army chaplin is now awaiting surgery at UHG - but his injuries are described as non life threatening.
The incident happened at around 10.45 last night and a male teenager is now in Garda custody.
In a statement, the Defence Forces has confirmed that shots were fired by on-duty soldiers.
It says this action was taken in strict accordance with protocols, with appropriate force, after a Defence Forces member was assaulted by a male civilian.
The victim suffered multiple stab wounds and it's understood he's waiting for surgery at UHG, though his injuries are described as not life threatening.
The chaplain has since posted on social media, thanking the public for their support, and saying he's OK but waiting for surgery.
The alleged assailant, aged in his teens, was restrained at the scene by soldiers until he was arrested by Gardaí.
He's still in custody at an unspecified Garda Station.
The focus of Garda investigators today has been on an area of ground a few meters inside the gates of Dun Ui Mhaoiliosa.
There was a considerable presence at the barracks this morning, with several soldiers manning the front gates as Gardai carried out their work.
We know the stabbing happened shortly before 1pm - but what's not known is if this was a random or targeted attack.