Dublin Bus is investigating footage of a young man hanging onto the back of a moving bus.
The footage was shared on social media this week.
A spokesperson for Dublin Bus has confirmed it is looking into the incident.
The footage is believed to have been taken as the bus was driving through Finglas this week.
In a statement, the company says the action shown in the footage is unsafe and extremely dangerous.
It says Dublin Bus strongly discourages anyone from partaking in such reckless behaviour that could result in serious injury.