A two-month-old baby girl has died and three relatives have been seriously injured in a stabbing incident at Parkinson on Brisbane's southside, police say.

Key points: Two-month-old baby girl dies after stabbing attack

Two-month-old baby girl dies after stabbing attack Baby's mother, grandmother and grandfather also injured

Baby's mother, grandmother and grandfather also injured Police are investigating the circumstances of the incident

At 2:30pm, officers were called to two homes in Watheroo Place and Mapleton Circuit at Parkinson after reports of a loud domestic disturbance.

When officers arrived, they found the infant, her 28-year-old mother, grandmother and grandfather with serious injuries.

The grandmother, aged in her 50s, was found inside the house, while the grandfather, also aged in his 50s, was found on the front lawn.

Both are visiting Brisbane from China.

The baby girl was treated at the scene before being taken to Lady Cilento Children's Hospital in a critical condition. The adults were taken to the Princess Alexandra Hospital.

The baby later died of her injuries, police said.

Police said the mother fled from the home to a neighbour's house in nearby Mapleton Court to seek help.

"One of the victims went to the secondary crime scene and that's where police were notified from there," Acting Police Inspector Sean Mackay said.

Two crime scenes have been established in Watheroo Place and Mapleton Circuit.

Dozens of police are investigating the circumstances and door knocking homes in the area.

A neighbour told the ABC she was shocked to come home and find such an incident unfolding in the neighbourhood.

"We're quite surprised to come home and find something like this on our doorstep," she said.

"Lots of police cars, ambulance, and the road cordoned off, we were pretty upset to see that."

Police are not saying if anyone is considered a suspect, but they have confirmed they are not looking for anyone else.

They remain with all three people at the hospital.