A man has been shot dead near Ballyhaunis.
The shooting took place just before midnight on Tuesday outside a property at Aghamore.
A man in his eighties has been arrested and is being held for questioning at Castlebar Garda Station.
The dead man is understood to be in his sixties.
Gardaí are appealing for witnesses to contact Claremorris Garda Station on 094 937 2080, the Garda Confidential Line on 1800 666 111 or any Garda Station.