A woman and two young girls are fighting for life after they were pulled unconscious from a suspicious house fire.

Flames erupted from the modern townhouse in Chadstone in Melbourne’s south-east on Wednesday night.

About 30 firefighters arrived at the scene to find flames burning through the roof of the two-storey house.

Neighbours informed rescuers that four residents were unaccounted for inside the home, Fire Rescue Victoria Commander Paul Eckholdt said.

“It was a difficult rescue for firefighters, given that they had to force entry into the property initially and then wearing breathing apparatus, and the conditions being quite hot and with virtually zero visibility,” he told ABC Radio Melbourne.

Firefighters searched through the smoke-filled home until they found two primary school-aged girls and a woman in her 30s in an upstairs bedroom.

“They were unconscious, so they were carried out and taken out to the front where Ambulance Victoria paramedics and firefighters were waiting,” Eckholdt said.

“They did have some burns, and they also had some airway burns as well.”

The girls were rushed to the Royal Children’s Hospital while the woman was taken to The Alfred. All are in critical conditions.

Authorities are treating the fire as suspicious. Fire investigators and an arson chemist will be at the crime scene on Thursday.

The home, one of two on the block, remains taped off. Police and firefighters remain on scene.

Most of the damage occurred to the rear of the property as the fire razed the home’s upper floor bedrooms and ensuite. Part of the roof has collapsed, while the rest of property has smoke and water damage.

-AAP