Gardaí and the Military Police are investigating the accidental discharge of a firearm by a member of the Defence Forces in Portlaoise.
A Garda spokesperson said it happened at a petrol station on the Abbeyleix Road at around 9:30pm on Wednesday.
The soldiers were armed with automatic assault rifles and were preparing to join a prison escort operation.
During the stop one of the soldiers accidently fired off a round into the floor of a jeep.
No one was injured in the incident.
In a statement, the Defence Forces said: “All members of Óglaigh na hÉireann are subject to the highest standards of weapons handling throughout their careers both at home and abroad.”
“Prior to commencing a prisoner escort, there was a weapon discharged by one of the personnel on duty.
“Breaches of procedure and safety in relation to firearms are investigated as a matter of course, with disciplinary action being taken where warranted.”