Ten trains on busy commuter routes in Dublin have been cancelled this afternoon due to unofficial action by drivers.
The trains on the line between Pearse Station and Balbriggan as well as services to and from Clonsilla have been affected.
Iarnród Éireann has advised passengers to use other services and to expect overcrowding on trains that are running.
Services from from Portlaoise to Heuston and from Heuston to Carlow were cancelled this morning as management and unions attend talks over rostering at the Labour Relations Commission.
The dispute involves drivers refusing to operate expanded services in Iarnród Éireann's new timetable.
The new timetable - with an increase in the number of trains being run - has led to difficulties with train crew rosters. Drivers at a number of depots decided last month not to work their scheduled rest days.
This evening's cancellations are: 14.45hrs Pearse-Balbriggan, 16.16hrs Balbriggan-Connolly, 17.07hrs Connolly-Balbriggan, 18.07hrs Balbriggan-Connolly, 14.46hrs Connolly-Clonsilla, 15.30hrs Clonsilla-Docklands, 16.20hrs Docklands-Clonsilla, 17.12hrs Clonsilla-Docklands, 17.38hrs Docklands-Clonsilla, and 18.14hrs Clonsilla-Connolly.