Gardai are investigating a soccer riot which occurred on the Luas when a group of Shamrock Rovers fans kicked and punched opposing fans.
The incident took place after a friendly game between Rovers and Shelbourne last Friday.
As many as seven Rovers fans set upon a Shelbourne supporter, while another two who tried to diffuse the situation took a heavy beating from the thugs.
The attack last Friday took place at 10.20pm between the Belgard and Kingswood stops on the Luas Red Line and gardai are investigating CCTV footage to try to identify the thugs.
One of the injured Shels fans spoke of the ordeal which occurred in front of a packed tram of innocent commuters.
"It was unbelievable, I've been involved in football for 20 years and I've never had an experience like last Friday night," the fan said.
"When they got on first they walked right down the carriage, they were scoping out who was on the tram, they picked out a Shelbourne fan and started throwing digs at him. He hit the ground and they started kicking and punching him.
"My friend and I tried to separate them and we stood over the poor guy on the ground and then they started hitting us.
"My mate had a busted nose and I got a belt over the eye, an ambulance worker told me after that the person who hit me had to have been wearing a large ring or a knuckle duster.
"I have two black eyes from the attack which was completely unprovoked, it happened so fast, all within one stop.
"They knew what they were doing. They started the row a minute before the next stop and then hopped off.
"The League of Ireland clubs and the FAI have to act now before someone is seriously hurt or killed in one of these attacks."
Shamrock Rovers FC have condemned the attack. Club spokesman John Byrne said: "Since the move to Tallaght we've enjoyed fantastic success and were not going to tolerate anti-social behaviour.
"Our club is on the way up and we don't want to be associated with this kind of thuggery. If they are identified they will never get anywhere near the stadium again, they're history."
Shelbourne FC have conducted an investigation into the incident and prepared a report for the FAI and the gardai.
"Our club chairman Joe Casey made an appeal to any Shelbourne fans that witnessed or were involved in the incident to email him with the details of what happened," said a spokesperson for the club.