Royal Air Force aircraft makes unapproved landing at Shannon
British diplomats have said a "communication breakdown" caused a Royal Air Force aircraft to make an unapproved landing at Shannon Airport.
The Hercules transport plane landed on 29 December without seeking clearance from the Irish government in advance.
Irish Minister for Foreign Affairs Charlie Flanagan said breaches of the procedures which grant permission for such landings were viewed with "the utmost seriousness".
The British Embassy in Dublin told officials that the aircraft landed in Shannon to re-fuel.
Mr Flanagan said he had instructed his officials to "request clarification" from the British Embassy.
"The embassy has confirmed in writing that the purpose of the landing was refuelling, and that the flight was unarmed; carried no arms, ammunition or explosives; and was not engaged in intelligence-gathering nor formed part of a military exercise or operation," he said.
"I have instructed my officials to discuss the matter further with the British Embassy with a view to ensuring that correct procedures are followed in future," he added.
Permission should have been sought in advance and assurances given that the aircraft was unarmed, carried no cargo of arms, ammunition or explosives and that it was not on an intelligence-gathering mission or a military exercise or operation.
Twenty-one other RAF flights followed the correct procedures to land in Ireland last year.