A suspect bomb has been found on a rail line in North Dublin.
Gardaí and the defence forces are at the scene north of Kilbarrack.
The line is closed between Raheny and Howth/Malahide.
Ongoing security alert near Kilbarrack: line closed Raheny to Howth/Malahide. Dublin Bus accepting rail tkts. (1/2)— Iarnród Éireann (@IrishRail) May 19, 2015
Drogheda Commuter services and Belfast Enterprise services are also affected.
Dublin Bus is accepting all valid rail tickets.
Services currently delayed through Howth Jn to facilitate Garda operation, update shortly— Iarnród Éireann (@IrishRail) May 19, 2015
Barry Kenny from Irish Rail said that the matter is being dealt with by Gardaí and the Defence Forces.
"A member of our line inspection team was walking the route just north of Kilbarrack station, he had concern about an object that he saw, so he alerted our control and we reported it to the Gardaí," said Mr Kenny.
"It was good vigilance on the part of our staff member. Gardaí and the defence forces are leading the operation."