Two men and a woman have been found dead at a property in Co Louth.
Gardai said one man had been arrested after they were alerted to a “serious incident” in Tallanstown on Monday morning.
Ireland’s Justice Minister Jim O’Callaghan said there was no further threat to the public following the “criminal act”.
A gardai statement said: “Three people – two males and one female (all adults) – were found deceased at the scene.
“The scene has been preserved for technical examination.
“The offices of the coroner and the state pathologist have been notified.
“A male, aged in his 30s, has been arrested and is currently detained at a station in the Garda North West Region under Section 4 of the Criminal Justice Act 1984.”
The statement said investigations were ongoing.
Gardai have closed a road leading to an isolated property at the scene.
A blue-and-white forensic tent has been set up close to the property.
Mr O’Callaghan said: “I have information, An Garda Siochana have passed on information that I have received to the office.
“I am conscious that it is a developing story and it is a sensitive issue but there is no further information I can put into the public domain at present.
“I think further information will become available in due course.”
He added: “What I can say and what gardai have said is that they are not looking for anyone else in respect of this criminal act.
“There is no ongoing threat to the public in Co Louth.”
Sinn Fein Louth councillor Pearse McGeough said on social media that there was “sad news coming out of Tallanstown this morning”.
He added: “I would ask people not to speculate until we know the facts.
“Our thoughts are with the friends, family and the community.”