There are fresh calls for a dedicated transport police for bus and rail services.

It comes after a teenager was stabbed on a train between Killester and Harmonstown in Dublin last night.

The National Bus and Rail Union (NBRU) has written to the Transport and Justice ministers, asking for the establishment of a Garda Public Transport Division.

NBRU General Secretary Dermot O'Leary suggested the issue of anti-social behaviour on transport services has reached 'crisis point'.

He argued: "The mood among transport workers has changed dramatically on the back of a number of recent assaults across both our train and bus services.

"They were encouraged by the Minister's initial response in early summer, [but] they are now of the view that they may have to take their own preventative measures, inclusive of assessing service provision in particular hot spots and in areas with a high prevalence of anti-social behaviour."

Labour Senator Aodhán Ó Ríordáin also suggested there has been a long list of 'troubling incidents' on the train line on the northside of Dublin.

He observed: “I welcome the fact that Minister Ross has indicated his willingness to explore the possibility of establishing a Transport Police Service.

"The proposal must be brought to fruition as soon as possible for the safety of commuters and staff on our public transport system.”

Meanwhile, Irish Rail spokesman Barry Kenny noted that anti-social behaviour is a growing issue.

Speaking on the Pat Kenny Show, he explained: "The vast majority of people do travel without any incident - but we've seen it from our own staff report and customer reports, it has been growing the last 18 months.

"We've increased our own private security resources and patrols by 35%. I would say last night's incident was very shocking for us, for the people on board.

"We also liaise with the gardaí - their response last night was excellent."