Commuter train and Dart services through Connolly Station in Dublin have returned to normal following an earlier disruption to services.
All northside trains to and from station, including Maynooth services, were stopped for a time this morning because of a signal fault which was blamed on vandalism.
Even after the problem was rectified and train services resumed, passengers experienced delays of up 30 minutes for much of the morning because of congestion.
Iarnród Éireann said the congestion caused by the fault was now over but apologised to passengers for the inconvenience.