Gardaí in Dublin are investigating a serious assault in the south inner City on Tuesday night.

A man in his 20's suffered serious injuries in an altercation with another man near the Rialto LUAS stop at St. James'' Walk.

The victim was taken to St. James' Hospital where he's in a critical but stable condition.

A man (19) was arrested at the scene and is being questioned at Kilmainham Garda Station.

Gardaí are appealing for witnesses to the incident.