Victoria Police are investigating a “horrific” house fire in Melbourne on the weekend that left a mother and three young children dead.

Firefighters were called to Tulloch Grove in Glen Waverley about 1.40am on Sunday after receiving multiple calls about smoke coming from the two-storey townhouse.

Police say Kaoru Okano and her daughters were found huddled together in the en suite of the home.

A man who survived the blaze is in The Alfred hospital in a serious but not life-threatening condition.

Crews found the garage on the ground level “engulfed with flames” and the home filled with smoke, Victoria Police Detective Senior Sergeant Neville Major said on Sunday.

“Tragically, four people have perished,” he said.

Senior Sergeant Major said police were still determining the man’s relationship to the victims, but it was believed he was related to the family.

He was intubated in the hospital and police did not expect him to be able to speak to detectives until at least Monday.

The police have been in contact with the Japanese embassy to help them update family members on the investigation.

Man shouting: ‘My kids!’ tried to go into burning building

A neighbour, Hanish Poonia, told the ABC he called emergency services after hearing a man shouting: “Fire! Fire! Help! Help!”

“He was trying to put out the fire with a hose but it wasn’t working so he tried to fill a big bin with water,” Mr Poonia said.

“After the emergency services came then he started shouting: ‘My kids! My kids! There are kids upstairs!’.”

He said the man then went into the burning building and had to be pulled out by firefighters.

“They told the [ambulance officers] that the man was trying to get inside and ‘we don’t want him inside’,” he said.

He said the man was burned on his back and his face was blackened.

“He was sitting on the road crying that ‘my kids are inside’,” he said.

Mr Poonia said he had seen the family come home about 11pm on Saturday.

“They were a lovely family. The lady was very good,” he said.

Tributes have been left for the family near the house following the tragic blaze. Photo: ABC

Neighbours woken by ‘one big bang’

Arson squad detectives were called to the scene and the exact cause of the fire is yet to be determined.

Neighbour Maria Tsakiris said she was woken in the early hours of the morning by “one big bang”.

“I thought it was a car accident,” she said.

She said when she got near the Tulloch Grove house, she could see ambulances and fire brigades surrounding the property.

“It was so, so scary,” she said.

About five minutes after hearing the bang, she said neighbours started hearing screaming.

“We heard screaming from somewhere, a male’s voice, and that startled me as well,” she said.

Ms Tsakiris said she and her daughter spent two hours on the street near the house, waiting to hear news of the three children before being told they had died.

“We were just really upset, really upset,” she said.

“It’s just horrific, horrific. It wasn’t even like a fire, it was more like a war zone out here. It was terrible.”

Debra and Bianca Ortolan, who live close to the townhouse, said they were woken by smoke filling their home and the sound of explosions.

They took in an evacuated family as emergency services worked to bring the fire under control.

“[It was] heartbreaking,” Ms Ortolan said.

“Not being able to do anything, you’re so helpless … we just all prayed that they got the kids and the mum out.”

Children’s clothes still hung on the washing line outside the house on Monday morning. Photo: ABC

Fire took two hours to bring under control

Fire Rescue Victoria assistant chief fire officer Costa Katsikis earlier said crews worked hard to battle the intense blaze in the early hours of the morning.

“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.

“Our thoughts go out to the family and friends impacted by this tragic event.”

Immediate neighbours of the townhouse were evacuated and it took more than two hours to bring the blaze under control.

Bianca Ortolan said the emergency services did an “amazing job” responding to the fire.

Senior Sergeant Major said police treated all fires as suspicious until there was evidence to suggest otherwise.

Anyone with information is urged to contact Crime Stoppers.