A Melbourne community is in shock after a four-year-old girl was mauled to death in her own home by a neighbour's pitbull terrier last night.

Ayen Chol was playing with her five-year-old cousin at her home in Lahy Street, St Albans, when the attack happened.

It is believed the dog had escaped from a neighbour's yard.

The little girl died at the scene despite ambulance officers' attempts to revive her.

Her five-year-old cousin and another 31-year-old female cousin were injured in the attack and taken to hospital.

The woman fought desperately to keep the dog at bay and suffered deep lacerations to her arms and hands. The five-year-old suffered bites to her face.

Neighbours described hearing screams from the house as the attack unfolded.

Police say the dog, an American pitbull-mastiff cross, will now be destroyed.

"This is a really horrible tragedy, and it will take some time for us to fully understand what has happened," Superintendent Graham Kent said.

"We're not sure at this stage how the dog got out from the house it belongs to. We're not sure how the dog got into the house where this happened.

"What we do know is that when it did go into the house, three people at least were injured, and one of those is a girl who is now deceased."

'They look mean, they usually are'

A police car sits outside the girl's house this morning. ( ABC TV )

Police say the dog's "devastated" owner quickly agreed to have it put down, and officers say they are yet to determine if any charges will be laid.

Superintendent Kent says police are trying to work out how the dog got loose.

"I don't mind saying, I hate seeing these dogs walking the streets. They look mean, they usually are," he said.

"However, to be fair to the owner of this dog, we need to go through a proper investigation and look at what the evidence then tells us, so far as the possibility of any offences is concerned.

"We're dealing with a seriously aggrieved family who have lost a child, and the owner of the dog who lives in that community and is devastated also."

Ayen's mother is being comforted by Sudanese community leaders, while her father is in Southern Sudan helping the country with its recently won independence.

A relative of the dead girl, Daniel Atem, says it is a terrible shock.

"She's a lovely girl, actually. All the time, she talks with people, she's talkative actually. She's talkative, she'll say anything," he said.

"It's a shock. Even the father, we didn't call him because it's terrible. When he will hear this, it will be very, very bad."

Crackdown promise

The death has prompted renewed calls for dangerous dog breeds to be banned, with the Victorian Government promising new laws to hold owners responsible if their pets are involved in attacks.

The state minister responsible, Peter Walsh, says councils will get more money to monitor dangerous dogs and the State Government will establish a "Dob in a Dog" hotline.

"I've spoken to the Attorney-General and we'll look at amendments to the Crimes Act so that people are responsible for whatever their dogs do in society," he said.

Colin Muir, the president of the American Pit Bull Cub of Australia, says the owner must bear the responsibility.

"Any idiot that wants the toughest dog in the street goes out and picks that dog. That's a real problem," he said.

"If you take a pitbull right out of the community, ban it, Get rid of every pitbull tomorrow, those idiots will just go and buy another dog.

"It's not a breed issue, it is about responsibility of ownership and it's about education," he told ABC Local Radio.

ABC/AAP