By Laura Lynott

Up to 20 youths wearing balaclavas stormed a train last night and brawled with knives and blocks of wood, as they spray painted a train, threatening passengers and causing around €4,000 damage.

In what Irish Rail has described as an “unprecedented graffitti attack” around a dozen youths blocked the doors of a Dart with pieces of wood at Clongriffin Train Station in north Dublin, preventing the train from moving.

Train passengers were threatened by the gang with pieces of wood as all hell broke loose on the train at around 10.30pm.

One eyewitness said there were about 20 youths wearing balaclavas involved in the vandalism.

"They had knives and sticks and started fighting each other. It looked like two gangs who were fighting over who’d spray paint the train - it was unbelievable and terrifying. It was the worst I’ve ever seen, incredible.”

One member of the public said: “A few of us wrestled one of the lads. He had a 2x4 (piece of wood). We didn’t know they had knives as well though.”

Some passengers were too traumatised to speak about the incident but Irish Rail confirmed this attack “exposes the lie that graffiti vandals are engaged in some sort of artistic endeavour.

“This was aggressive and threatening criminal activity.”

The gang fled at Clongriffin, running up the train tracks as gardai were alerted but no arrests have yet been made.

Gardai and Irish Rail are reviewing the CCTV footage today.

Irish Rail said it only had information that around a dozen youths had stormed the train but it confirmed there had been “some suggestion a second grafitti group became involved in an altercation with the vandals.”

Images provided to the press from the public show the train has been spray painted and gardai inspecting the carriage.

Passengers were instructed to disembark the train as the damage to the carriage was extensive and there was a strong smell of spray paint within the train.

Irish Rail staff asked passengers to board another train as gardai searched for the youths.

Irish Rail and the Gardai did not yet have information about knives being carried during the assault on the train but passengers told the media the youths had knives.

A regular passenger said “This happens every two weeks,” though another passenger stated he had never seen anything of this magnitude before on a train.

An Irish Rail spokeswoman said: “A deliberate and orchestrated graffiti attack took place on an in-service DART last night at Clongriffin Station.

“A group of approximately a dozen vandals completely spray painted a DART and blocked doors individually and with pieces of wood preventing the DART from departing. While thankfully no customers were hurt some were threatened by the vandals with pieces of wood.

“There is some suggestion that a second graffiti group became involved in an altercation with the vandals but we will be reviewing cctv and supplying Gardai with all footage to assist in prosecutions.

“While graffiti attacks are unfortunately an ongoing issue we have to tackle, the scale of this on an in-service DART was unprecedented. In reviewing this with Gardai we will also review security presence to counteract issues of this kind. We urge anyone with information to contact the Gardai.

“This incident clearly exposes the lie that graffiti vandals are engaged in some sort of artistic endeavor. This was aggressive and threatening criminal activity.

“In light of this we are reviewing security at Clongriffin and will have immediate additional security pending the review.”

A Garda spokeswoman said: “Gardai are investigation an incident of criminal damage to a train at Clongriffin Dart Station last night. Youths allegedly spray painted a carriage but were gone on arrival of gardai. Investigations are ongoing.”

The dart had been travelling from Dublin to Malahide.