Gardaí say they're exploring if the stabbing attack at Renmore Barracks was motivated by terrorism.
The special Detective Unit of An Garda Siochana is involved with the ongoing investigation.
In a statement, An Garda Síochána says it wishes to reassure the public that at this time, it is not believed the incident is part of a wider conspiracy.
Meanwhile, the army chaplin injured in the attack is now awaiting surgery at UHG - but his injuries are described as non life threatening.
A male teenager remains in custody, with his detention extended.
In a statement, the Defence Forces has also confirmed that shots were fired by on-duty soldiers last night.
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 chaplain has since posted on social media, thanking the public for their support, and saying he's OK but waiting for surgery.
The focus of Garda investigators today has been on an area of ground a few meters inside the gates of Dun Ui Mhaoiliosa.
There's been a considerable presence at the barracks today, with several soldiers manning the front gates as Gardai carry out their work.
We know the stabbing happened shortly before 1pm - but what's not known at this time is if this was a random or targeted attack.