A gang of thugs hurled a torrent of abuse and threw two bottles at a pregnant woman inside a Luas tram in the capital.
The shocking incident happened on the Luas Red Line on Easter Monday.
The woman complained to the driver, who called Gardai. She was left shaken, but otherwise unharmed.
Gardai are investigating the incident and have appealed for sharing and anyone who witnessed the act of thuggery to contact them on their Confidential Line on 1800 66-61-11.