'Beautiful angel': Heartbreaking post before baby stabbed to death

Only two months ago 28-year-old first time mother Yuanyuan Cao proudly announced on social media the birth of her beautiful bouncing baby girl, Queenie.

"15/10/15, 3:28am, my little princess was born 3.1 kg at mater hospital," she happily posted.

Tragically, Queenie was fatally stabbed yesterday just nine days short of the three month anniversary of her birth.

The newborn was rushed to Lady Cilento Children’s Hospital late yesterday afternoon suffering critical stab wounds however tragically doctors were unable to save the baby.

Her mother, Yuanyuan Cao is currently in the Princess Alexandra Hospital in a serious but stable condition.

The newborn’s grandfather remains under police guard while in the intensive care unit.

It is understood that the grandparents were visiting their daughter from China following the baby’s recent birth.

At vigil will held tonight at a park near where the horrendous attacks occurred yesterday in the Brisbane suburb of Parkinson.

The community is in shock following the fatal attack yesterday.

It is believed that Ms Cao has been married for three years and Queenie was her only child.

Police forensic teams have been combing through the house in an effort to search for evidence.

Earlier today shocking video filmed by a stunned neighbour was released of the infants grandfather covered in blood stumbling around a quiet suburban street in Brisbane after a brutal stabbing attack which killed his baby granddaughter.

Video obtained by the Courier Mail reveals the girl's grandfather staggering across the road apparently covered in blood as concerned, confused onlookers ask questions about what happened.

"Everything alright?... Was it a fight?" a male voice can be heard as the man has trouble placing his feet on the pavement.

Shortly after, the video shows the man being held down by police in the driveway of a home.

"The girl's up there," a voice behind the camera says, alerting a police officer who changes direction and moves further up the street, holding his hand to the weapon in his holster.

The neighbour who shot the footage spoke with 7 News stating, “As soon as I heard that baby my heart dropped.”

“I arrived literally five minutes before the incident. I started hearing the screaming, the yelling. At the time I thought it was happy and playful ‘cause it’s still holiday season. Then the screaming became serious and it became wailing. Blood dripping everywhere.”

Police were called to a Watheroo Place home around 2.30pm after the baby's mother fled to a nearby house in Mapleton Court to seek help.

Upon arrival at the Watheroo Place home, police located the baby girl, who was treated at the scene before being taken to the Lady Cilento Hospital.

Her grandmother was found unconscious in the house and the grandfather was found in the front yard. Both were transported to Princess Alexandra Hospital with life-threatening injuries.

The grandparents, aged in their 50s, are in critical condition.

A crime scene has been established, with streets Watheroo Place and Mapleton Court closed-off while police investigate.

"The circumstances surrounding the incident are still under investigation, which will include detectives speaking with the three adults when their medical conditions allow," police said in a statement.

"At this time, it is believed there are no other people involved."

Earlier, Acting Inspector Sean McKay said police were not prepared to name a suspect but said they were "not looking for anyone else".

"One of the victims went to a secondary crime scene which is Mapleton Place and that's where police have been notified from there," the detective said.

"We'll be trying to talk to some of the injured people if possible up at the hospital."

Neighbour Samantha Govendor told 7News that residents were shocked when they arrived home to find their street full of police cars and swarming with officers.

"Generally, we are pretty distressed by what has happened," she said.

"It is a quiet street, beautiful suburb, and we've just come home to see all these police and ambulances and stuff."

A major incident taskforce has been set up to investigate the circumstances of the stabbing.

National domestic violence helpline: 1800 737 732 or 1800RESPECT