Protesters breached security at Shannon Airport before dawn yesterday to pour holy water on a runway and pray.
The protesters also built a shrine to the victims of the Iraq war and planted potatoes.
They were arrested inside the perimeter fence at around 5.30 a.m. after a search by soldiers, gardaí and airport police. The security breach came despite patrols of the perimeter fence and key facilities within the airport.
A spokeswoman for Aer Rianta said the protesters had been apprehended "very quickly", adding that all such breaches are considered very seriously.
A spokesman for the Army said there was no suggestion the protesters would have gained access to any of the key facilities at the airport being guarded. The protesters were apprehended by a roving patrol and were arrested by gardaí at the scene.
"It was very dark at the time and the perimeter fence is six or seven miles long. There is no way you would be able to patrol the whole thing unless you had absolutely blanket security," he said.
Gardaí said two protesters had been detained under Section 4 of the Criminal Justice Act.
The latest protest came on the day that Ms Karen Fallon was released from Limerick prison. She was one of five protesters from the Catholic Worker Movement jailed for a similar protest at the airport in February.
The other four protesters were released early last month but Ms Fallon was held longer because she refused to agree to certain bail conditions.
In January Ms Mary Kelly (50) broke into Shannon Airport and attacked a US Navy cargo plane with an axe.
