A public call for the establishment of a special garda unit to patrol Dart services in Dublin was prompted by serious disruption on a north-bound train in the city.
Councillor Cormac Devlin said it was outrageous that passengers were distressed by a violent incident on a train at Salthill and Monkstown station which caused trains to be delayed for 35 minutes on Sunday night.
A fight broke out involving a group of youths at around 9.30pm. Gardai were called to the scene after a commuter alerted the driver to what was happening.
The Dart was delayed as the garda investigation got underway. There were no arrests at the scene and no further complaints were made.
Cllr Devlin said that the incident shows the need to set up a garda transport unit to police public transport.
"I've seen too many of these types of incident on all types of public transport," said Cllr Devlin. "Security on its own isn't enough, something needs to be done.
"The Minister for Justice needs to talk to the Commissioner to get this kind of unit set up," said the Dun Laoghaire Rathdown Fianna Fail councillor.
"It is unacceptable that Dart services can be held hostage by a group of thugs. The public have every right to expect a reliable service and feel secure as they go about their business.
"I would like to commend Irish Rail staff and the gardai for their handling of the issue.
"However, this disturbance should serve as a wake-up call for policymakers.
"This is not the first disturbance on the Dart service this year. We regularly hear reports about the public feeling unsafe on the service, particularly at night time.
"While Irish Rail employs dedicated security, these staff do not have power of arrest.
"I am calling on the Minister for Justice to establish a dedicated garda transport unit that would police the capital's transport infrastructure.
"The very presence of uniformed officers would prevent many minor issues occurring and would ensure more serious issues could be dealt with more quickly," he added.
A spokesperson for Irish Rail said that up to five people may have been involved in the incident, some of whom were under 18.
There were large crowds on the Dart returning home from the Bray Air Display that took place on Sunday.
"It looks like it was about five people involved in the incident," the spokesperson said.
"They may have been part of larger groups who were shouting or certainly adding to the general tension but there was about five people who were fighting on board just as it was approaching Salthill/Monkstown station.
"It was reported to the driver.
"He alerted the gardai and he held the train at Salthill Monkstown while the gardai arrived.
"All of the passengers that weren't involved in the groups that were engaging were moved to other carriages.
"So gardai came along and addressed the situation. The train went on after about half-an-hour."
Dublin TD Olivia Mitchell, whose purse was stolen while she used the Luas earlier this year, said she believed that gardai have patrolled train stations and trains along the Dart line.
She said more gardai were joining the ranks and more patrols on the city's train services would be welcome.
Gardai, both uniformed and plain-clothes, were involved in a crackdown on crime on Luas trams earlier in the year.