A post mortem examination's taking place today on the body of a baby boy who was killed in te Ardoyne area of north Belfast on Tuesday night.
A two-year-old girl's fighting for her life in hospital, after being seriously injured in the incident.
A 29-year-old woman was arrested on suspicion of murder and attempted murder, and remains in police custody.
It's understood the children's father returned home from England yesterday.
Gardaí Warn Of Rising Email And Retail Scams In Wicklow
Minister Meets Arklow Merck Staff as Closure Talks Continue
Bray Teen’s Bail Revoked Over Breaches Linked to Local Man’s Death
Devastating Blow As 100 Jobs To Go As Merck Life Science Plant Operations To Close In Arklow
178 Wicklow Homeowners Have Successfully Tapped Into The Vacant Property Refurbishment Grant