Two men drowned when their fishing boat overturned on Saturday on Lough Erne near Enniskillen, Co Fermanagh.
Other accidental deaths at the weekend include that of an infant in a house fire, also in Co Fermanagh, and a road accident death in Co Offaly.
The alarm on Lough Erne was raised and the search began after the men's 16ft boat was discovered overturned in the lough on Saturday evening.
The first body was discovered yesterday morning north of Devenish Island near Enniskillen during a search operation involving police and coastguard on both sides of the border.
An Irish Coastguard helicopter from neighbouring Co Sligo was deployed in the search, and crew from Enniskillen inshore lifeboat and members of Lough Erne Coastguard Rescue Team were also involved.
Later yesterday, divers recovered the second body shortly after 4pm.
It is believed the first man whose body was recovered was the owner of the boat. Locals said he was in his 40s and regularly went out on the lough.
Police were last night trying to establish the identity of the other victim. Neither of the two men was named by the PSNI.
With Lough Erne proving an increasingly popular spot for tourists and water sports enthusiasts, Environment Minister Arlene Foster said the tragedy would be deeply felt in Enniskillen and the surrounding area.
"There have been tragedies on the lough in the past. It is a terrible thing to happen and my thoughts are with the families of the two victims at this time," the Fermanagh and South Tyrone MLA said.
An eight-month-old baby girl died yesterday in the fire at a house in Drumbawn, near Enniskillen in Co Fermanagh.
Members of the emergency services were called to the house at about 10am to deal with the fire. The name of the child has not yet been released. Detectives have been carrying out an investigation to establish the cause of the fire.
It is understood that neighbours raised the alarm when they saw smoke coming from the house.
The death of the baby girl was described as a tragedy by SDLP Fermanagh and South Tyrone Assembly member Tommy Gallagher.
"The community in Drumbawn is in a state of shock over this fire," Mr Gallagher said.
"I am very sorry and my sympathy goes to the parents and the wider family of this child. It is a terrible event."
Gardaí in Tullamore yesterday named the woman who was killed in a road traffic collision on Saturday evening in Daingean, Co Offaly.
She was Theresa Herbert, 53, from Lowtown, Robertstown, Co Kildare. The crash involved two cars and Ms Herbert was driving one of the vehicles, according to a Garda statement.
A man in his 50s was airlifted by a coastguard rescue helicopter to Mayo General Hospital in Castlebar around 1.30pm. yesterday after falling near the summit of Croagh Patrick.