Gardaí are investigating after a teenager died following a hit and run accident in Dublin.

It happened on the R139, Old N32, in Coolock at around 9.35pm on Saturday.

The pedestrian suffered serious injuries when he was struck by a car.

He was taken to Children's University Hospital, Temple Street - where he was later pronounced dead.

Gardaí say the car involved in the collision failed to stop or remain at the scene.

It was located and seized by gardaí a short time later, close to the scene.

A man aged in his mid-20s was later arrested in connection with this investigation.

He is currently detained at Finglas garda station under Section 4 of the Criminal Justice Act 1984.

The R139 was closed for a period of time to facilitate Garda Forensic Collision Investigators, but has since re-opened.

Gardaí are appealing for witnesses or anyone with information to contact them at Coolock garda station on 01-666-4200, the Garda Confidential Line at 1800-666-111 or any garda station.

Separately, gardaí in Blanchardstown are investigating a fatal collision at approximately 6.50pm on Hartstown Road.

Two motorcyclists collided and one man in his early 20s was removed to Connolly Hospital where he died a short time later.

The second motorcyclist was uninjured.