A child then got hold of the discarded firearm and discharged it, it is understood.

But another person who was in the area then reportedly took the gun from the child and fled.

Two males - a man in his 20s and juvenile in his teens - have been arrested and gardaí are investigating the incident.

"Gardaí responded to reports of a firearm incident in Ballymun, Dublin 9, today at approximately 3pm," a statement from Garda Headquarters said.

"Gardaí arrested two males, one in his 20s, and a juvenile in his teens, who are currently detained under Section 30 of the Offences Against the State Act 1939 in a Garda Station in the Dublin region."

There were no reports of injuries in relation to this incident.

Investigations are ongoing.