Disrupted rail services to and from Cork are expected to return to normal by lunchtime following the end of unofficial action by National Bus and Rail Workers' Union (NRBU) members.
The industrial action started at midnight last night following a union meeting for NBRU members across all grades in Cork late yesterday evening.
Mr Liam Tobin, general secretary of the NBRU, told ireland.com: "There was a relatively minor incident in Cork on Tuesday night when brief unofficial action was taken regarding an ongoing disciplinary matter.
"It was sorted out and an agreement was reached with senior management in Dublin, including a guarantee that there would be no action taken against those involved.
"Local management in Cork disregarded this agreement and issued disciplinary proceedings against eight people, even though there was a meeting scheduled, about the matter, for this morning," he said.
Iarnród Éireann recalled the disciplinary forms and a return to work was negotiated. A meeting will take place between the company and the union early this afternoon as a result of the return to work.
Iarnród Éireann apologised to customers for any inconvenience caused. Services were disrupted on Mallow/Cork/Cobh, Cork/Dublin and Cork/Tralee routes.