A man is in a serious condition in hospital after a stabbing in a house.
Gardai are investigating the serious assault in Mullaharlin Park, Dublin Road, Dundalk, at 3.30am.
A second man, also aged in his 30s, was arrested at the scene by investigating Gardai and is currently detained at Dundalk Garda Station under Section 4 of the Criminal Justice Act, 1984. A garda spokeswoman said the scene has been preserved for a technical examination.
The victim is being treated at Our Lady of Lourdes Hospital.