Neighbours heard screaming coming from a townhouse where three children and a woman died in a horrific house fire that erupted in Melbourne overnight.
The bodies of a mother and her three young girls were found inside the remains of the home in Glen Waverley, in the city's southeast, after a blaze tore through the property early this morning.
Detective Senior Sergeant Neville Major told reporters their bodies were found in an upstairs ensuite, and it appeared they had been "huddled together" as flames spread through the house.
Sources have confirmed the mother was Kaoru Okano.
A man, who police say is related to the Japanese family, escaped the inferno with serious burns.
"He himself has been burned and taken to hospital," Senior Sergeant Major said.
"He is currently intubated and unable to assist us with our inquiries. And we will not be able to speak with him for the next 24 to 48 hours."
Arson Squad detectives were still combing the scene this afternoon as police work to determine the cause of the fire.
"Investigators have been told the fire started in the Tulloch Grove property just after 1.40am," Victoria Police said in a statement.
"Sadly, a woman and three children have been located deceased at the residence and are yet to be formally identified."
Senior Sergeant Major said police treated all fires as suspicious "until we can determine that they're not".
"It's very tragic and it appears they had all been huddled together in the ensuite."
A neighbour, Alida Soteldo, told NCA NewsWire she was "devastated" by the tragedy that has rocked the suburban street.
"I woke up at 1.30am with all the noise from the fire trucks and went out and spoke to a couple of residents from that block, which were evacuated from their apartments," she said.
"They said they woke up with people screaming but no one knew there were any casualties until this morning on the news."
More than 30 firefighters were called to the scene after witnesses reported smoke billowing out from the two-storey townhouse.
It is believed the fire started in a downstairs garage and spread through the home.
"The home sustained significant fire damage," Fire Rescue Victoria said in a statement.
"Occupants from neighbouring residences were evacuated as a precaution, their properties also inspected for fire damage."
Fire Rescue Victoria assistant chief fire officer Costa Katsikis said his thoughts were with those impacted by the "tragic event".
"Upon arrival they were confronted by a fierce fire, a high fire load, a very hot fire that tragically ended in the loss of four lives and one person taken to hospital with smoke inhalation," he said.