A 31-year-old man has been arrested in connection with the deaths of two women in their 20s and two children in Newcastle West, Co Limerick.
The four were found dead in a house in Hazel Grove Estate, Gortboy, shortly after 1.30pm. It is believed they were stabbed to death.
One of the women is thought to be the mother of the children - a three-year-old boy and a girl who was five months old.
Gardaí were called by a member of the public to the house this afternoon. When they entered the house at around 1.50pm, they discovered the four bodies.
The two children were found upstairs, while the two women were discovered downstairs. The bodies are still at the scene.
The house has been sealed off pending a forensic examination. The State Pathologist's Office has been alerted.
The man is being questioned at Henry Street Garda Station in Limerick.
Gardaí have appealed for anyone who may have seen anything unusual in the area to contact Newcastle Garda station on 069-20650 or the Garda Confidential Line 1800-666-111.
Cathaoirleach of Limerick County Council Cllr Richard Butler said: 'Today is a black day for the people of Newcastle West and I would call on the people of County Limerick and indeed, the rest of the country to pray for the loved ones of those whose lives have been so tragically cut short.
'Newcastle West is a close knit community that works together in making the town a great place to live, work and visit.
'The community is in a state of shock and disbelief at this tragedy.'