A man in his 60s is in a critical condition following an assault in Westport, County Mayo.
The incident happened at around 1.20am this morning, following an altercation on High Street.
A man in his 20s has been arrested and is being questioned by gardaí.
It is understood the injured man is originally from Co Roscommon, but has been living in the Westport area for some time. He is being treated at Mayo University Hospital in Castlebar.
Garda forensic teams are carrying out an examination of the scene.