Iarnród Éireann has said DART services will be disrupted until tomorrow due to a power issue with overhead lines at Grand Canal Dock.
Rail services between Connolly and Dún Laoghaire stations were cancelled from 9pm, having earlier been suspended between Pearse and Dún Laoghaire, while staff work to repair a "significant issue to overhead line equipment".
"Disruption is expected to continue for an extended period of time, including during this evening's peak service," a statement from Irish Rail said.
Iarnród Éireann's Head of Corporate Communications Barry Kenny told RTÉ News this afternoon that the cause of the damage was unknown and staff are investigating.
DART services were continuing to operate between Howth/Malahide and Connolly, and between Dún Laoghaire and Bray/Greystones, but commuters were advised to expect delays.
The Rosslare intercity service were also impacted by the disruption.
Bus transfers were in place from Connolly Station to Bray, with trains operating to Wexford and Rosslare Europort.
However, Iarnród Éireann warned significant delays may result due to availability of buses and traffic conditions.
It added: "Northern commuters shall operate to/from Connolly/Pearse-Drogheda.
"Maynooth/Hazelhatch services will operate to/from Connolly/Pearse.
"Knock-on delays to all services in the city centre can be expected due to congestion on the line."
Irish Rail apologised to commuters for the disruption, adding that Leap Cards can be used on all TFI transport in the affected area, subject to capacity.
