Three serving members of the Defence Forces have been convicted of conduct "to the prejudice of good order and discipline of the forces" arising out of footage uploaded by one of them to the YouTube website last May.
The three have received fines totalling €600 and will have the charges placed on their army record.
This follows a hearing which took place on Thursday, during which the men appeared before their commanding officer as part of a summary investigation. All of the soldiers accepted the findings of the investigation.
The controversial footage showed two Irish soldiers "mock" aiming their weapons at a group of local people in Liberia.
It also appeared to show one of the men standing next to a vehicle while two others fired machine guns at a crowd in a nearby field.
Most of the group then took cover and the soldiers were seen laughing as they walked away. The section had been dubbed with the sound of fake machine-gun fire.
However, it is thought all of those involved were aware it was a "prank".
Cmdt Gavin Young of the Army Press Office said one of the convicted soldiers had a charge proven of uploading this video on to the internet, contrary to defence forces instructions. He was fined €250.
A second soldier had two charges proven of pointing his loaded weapon in the video at members of the public and at members of the Defence Forces and was fined €200.
The third had a similar charge of pointing his loaded weapon at members of the Defence Forces upheld and was fined €150.
All three were charged under section 168 of the Defence Act, which relates to conduct to the prejudice of good order and discipline of the forces.
They had faced a maximum fine of three days' pay as determined by pay levels for their current rank.
But it is understood that only one of the fines, for €250, was near to the maximum allowable under a summary investigation. The footage of the "prank" in Liberia was available on the YouTube website until last June, when it was removed.
At the time of the incident, which it has since transpired took place in October 2006, the three soldiers were serving with the 95 Infantry Battalion's UN Mission in Liberia (UNMIL).
All three are currently stationed with the 3rd Infantry Battalion at Stephens Barracks in Kilkenny.
"This incident was very disappointing, especially in light of the Defence Forces' reputation gained from overseas service, and in particular that earned by the seven battalions which served with UNMIL from November 2003 to May 2007," Cmdt Young said.