Up to ten teenagers are believed to have been involved in a serious attack on a man at a Luas stop in the city centre.
Gardaí are appealing for witnesses to come forward.
This assault happened at George's dock Luas stop shortly before 9pm on Sunday night.
A man aged in his 20s suffered serious head injuries and was taken to the Mater Hospital where he remains in a critical condition.
The Irish Independent reports the 29-year-old was approached by a group of up to 10 teenage boys before he was set upon and had his e-scooter stolen.
No arrests have been made and Gardaí are appealing to anyone who was in the IFSC area between 7 and 9.30pm on Sunday night to get in touch.
The scene was examined yesterday morning forcing a partial shutdown of the Luas for a time.