Gardaí have appealed for witnesses to an assault on Camden Street Upper in Dublin city centre early this morning.
A French man, believed to be in his 20s, is being treated for head injuries in St James's Hospital after the incident.
He and two of his friends were involved in a row with three men, believed to be in their 20s, shortly after 4am.
The three suspects left the scene in the direction of Rathmines.
Gardaí have appealed for anyone who was in the Camden Street area between 4am and 5am to contact Kevin Street Garda Station on 01-6669400.
Separately, a 42-year-old man was stabbed during an attack in Coleraine in Co Derry last night.
He was assaulted around midnight close to the town centre.
The victim was taken to hospital, but his injuries are not believed to be life-threatening.