The distraught grandmother of two children found dead in an apparent murder-suicide involving their father has urged people suffering depression to get help.
The three-year-old boy and five-year-old girl found dead in their Perth home had been seen by neighbours hours earlier on Thursday looking like normal children happily playing on the front lawn.
The children's 35-year-old father was in a critical condition in hospital under police guard on Friday night following the deaths that have shocked Perth.
It was likely the second such incident in Australia in four days.
The bodies of 44-year-old father Fernando Manrique, 43-year-old mother Maria Lutz, their 11-year-old daughter Elisa and 10-year-old son Martin were discovered in an apparent murder-suicide in their Sydney suburban home on Monday after police forced entry.
In Perth the grandmother and mother of the children's father said police had visited her at 4am on Friday with the devastating news.
"I thought I had a dream or something but when you face it and it is real ... it just hits you, especially with two little ones, grandchildren ... where do we go from here?" Georgina told ABC radio.
"If you are having problems, if you are feeling depressed, please God, talk to someone about it."
Police Detective Inspector Peter Clements said the investigation was in its infancy so he could not say what had happened or why and the names of those involved have not been released.
But police believe the father is responsible and his injuries were self-inflicted.
"His injuries were fairly significant requiring some fairly intense medical attention," Det Insp Clements told reporters.
Det-Insp Clements said it was too early to say how the children had died.
"We are still investigating the circumstances around why we were there and how we ended up there," he said.
The children's mother also lived at the home but was not present when police were called, had to force their way in and were confronted with the grisly homicide scene at the home at coastal Yanchep on Perth's northern outskirts at 10.30pm on Thursday.
"We have a family liaison officer appointed to her, we are in direct contact with her now, she is obviously very, very distressed," Det Insp Clements told reporters.
"We are doing what we can at this point to provide support not only to her but the police officers who attended, it was obviously quite distressing."
A next door neighbour told he heard a scream while having dinner at 6.15pm but thought it was from the TV, which he later told detectives.
"I heard a girl's voice or a woman's voice, high pitched and a scream," he said.
The family had moved in about 12 weeks ago but he had not seen the mother, who was a mining fly-in fly-out worker, and said the father kept to himself.
The neighbour, who did not want to be named, said the children were seen playing on the front lawn on Thursday afternoon, hours before they were killed.
The street Flight Vista is in a golf course estate with many properties still under construction and residents who are new to the area.
Bunches of flowers have started to be placed in the street.
