Gardaí (Irish police) have launched a murder investigation after a woman and young boy died in a house fire in County Offaly.

They have been named as 60-year-old Mary Holt and four-year-old Tadhg Farrell.

The blaze occurred at a house in Castleview Park, Edenderry, at 19:45 local time on Saturday.

A second woman, aged in her 50s, is in hospital with serious injuries, gardaí have said.

Supt Liam Geraghty said that gardaí “believe that the house was attacked by a person or persons unknown and that the fire was deliberately started”.

“This was a reckless, callous and murderous attack on a family home,” he said.

The house has been declared a crime scene and is being examined by the Garda Technical Bureau.

The office of the local coroner and the state pathologist have been notified.

An Garda Síochána (the Irish police service) said the remains of both deceased have been removed from the scene and post-mortem examinations will be carried out.

Police appealed for anyone with information or who has dash-cam footage who was in the vicinity of Castleview Park or adjoining roads between 19:00 and 20:00 local time on Saturday to contact them.

Minister for Justice Jim O’Callaghan described it as a “deliberate callous attack”.

“There is no place in a civilised society for such heinous violence,” he said.

“I join An Garda Síochána in appealing to anyone with information to come forward.”

Local Independent Ireland councillor Fergus McDonnell said the whole community has been left “absolutely distraught”.

Speaking to Irish broadcaster RTÉ on Sunday, McDonnell said he knew the people who died personally.

“The families are ordinary, salt-of-the-earth people, hard-working, and for something like this to happen, it’s just unreal.”

In a post on social media, Independent TD (member of parliament) Carol Nolan said it was “very sad news” that people have lost their lives.

“My thoughts and prayers are with the family, friends and the community of Edenderry,” she said.

“This is truly heartbreaking and devastating news.”