Update: 11.18am: Dart services have now resumed after a "tragic incident" at Dublin's Howth Junction station this morning.
Services were suspended for three hours in North Dublin after a person on the line was struck and fatally injured by a train.
Irish Rail says all Dart and commuter trains are now running but delays can be expected.
Line now reopening through Howth Junction - full DART, Commuter and Enterprise services to resume. Delays remain but will ease— Iarnród Éireann (@IrishRail) May 15, 2018
7.13am: There are major delays this morning on Dart services and commuter trains in Dublin after a "tragic incident" at Howth Junction station.
Irish Rail says that emergency services are attending the scene at the station and that the disruption is expected to continue throughout the morning at peak travelling times.
Speaking on RTE's morning Ireland, spokesman for Irish Rail Barry Kenny said that the incident occurred at approximately at 6.20am this morning when a train "struck and fatally injured" a person on the line.
"It would not be unusual for the line to be closed for two, two-and-a-half hours," he said.
There are no Dart services operating between Malahide/Howth and Harmonstown.
Northern Commuter trains are operating from Newry/Dundalk/Drogheda to Malahide only while the Belfast Enterprise will have a bus transfer in place between Dublin Connolly and Drogheda.
Dublin Bus will accept rail tickets but significant capacity issues are expected.
Update: tragic incident at Howth Junction being attended by emergency services
No DARTs between Malahide/Howth and Harmonstown
Northern Commuter operating Newry/Dundalk/Drogheda to Malahide only
Dublin Bus will accept rail tickets but significant capacity issues expected— Iarnród Éireann (@IrishRail) May 15, 2018
They have since warned passengers that their services are very busy and that they have their full fleet deployed to ease the overcrowding.