Camp Shamrock, where hundreds of Irish peacekeepers in Lebanon are based, was struck by a rocket last night.
The Chief of Staff for the Irish Defence Forces confirmed the incident while speaking in Athlone.
Camp Shamrock is the base for hundreds of Irish peacekeepers.
In a statement, the Defence Forces reassured families of the peacekeepers and the public that comprehensive force protection measures are in place in facilities in Lebanon.
"These measures have proven effective in ensuring the safety of our personnel during this event, and we are continuously working to mitigate any risk to our personnel.
"Our command staff is continuously monitoring the situation and are conducting a thorough assessment of the incident. We are working closely with our international partners to gather additional information and evaluate any potential future risks," it added.
"We understand that news of this incident may cause concern among the families of our deployed personnel. We want to emphasise that the safety and wellbeing of our troops remains our highest priority," it said.
It is situated about 7km from the border with Israel, and is close to towns and villages which are controlled by, or sympathetic to, the militant group Hezbollah.
Lieutenant General Sean Clancy said: "It was our assessment, [that the rocket was] travelling from north to south into Israel."
"A lot of these are undirected, unguided and therefore unpredictable rockets, and they have been known to fall out, being taken down by the iron dome.
"It did fall in an unoccupied area of the actual camp itself and caused minimal, minimal damage on the ground."
He said all Irish personnel are safe and well.
The rocket was a Russian-made Katyusha rocket.
Taoiseach briefed on incident
Taoiseach Simon Harris was briefed throughout the night on the situation at Camp Shamrock.
In a statement he said: "Thankfully everyone is safe but it is completely unacceptable that this happened.
"Peacekeepers are protected under international law and the onus is on all sides to ensure that protection. We continue to monitor the situation closely."
He added: "This is an extremely serious situation."
Tánaiste and Minister for Foreign Affairs Micheál Martin said the incident illustrates the risks that Irish troops face in a "very challenging environment".
"That is why force protection is extremely important.
"We are pushing very strongly for a de-escalation in the region, that is absolutely essential for the people of the region and also for the world.
"We need to avoid an Israel-Iranian conflict as well, because that could have very serious consequences for the world," he said.
"We cannot understate the importance of all sides pulling back from the brink now and engineering a ceasefire and working through a peaceful path.
"We're very conscious of the risks that are involved. We're also conscious that unlike Gaza, we have eyes and ears on the ground in Lebanon to bear witness to what is happening."
Earlier this month the commander of Irish peacekeepers in south Lebanon said that the targeting and injuring of United Nations soldiers was "totally unacceptable".
A number of peacekeepers have been injured since Israeli troops entered Lebanon in an escalation of its conflict with Hezbollah.
At one point, Israeli soldiers took up positions close to an outpost UNP 6-52 - which is manned by 30 Irish troops close to the border between Israel and Lebanon.
