A NINE-year-old girl badly burnt while playing in a Sydney park may have accidentally set herself alight, though police are still appealing for witnesses.

Traumatic ... police counsel the girl's father. News Limited picture.
However, police have yet to rule out that Sarah Allan was deliberately attacked by two masked teenagers seen running from the park as she began screaming for help.

Sarah suffered serious burns to her torso, legs and her underarms yesterday afternoon as she played just metres from her four younger siblings in Surgeon Park at Minto, in Sydney's south-west.

Police today revealed they were examining the possibility the youngster set herself on fire accidentally, despite witness reports of the fleeing teens.

"If it's accidental then it's been a tragic accident and if it has been deliberate we will do everything within our power to follow up on that," Macquarie Fields local area commander Superintendent Mark Rattenbury said.

Sarah, who remains in Westmead Children's Hospital, has spoken briefly to police, but Supt Rattenbury would not elaborate on what she had told them, saying only it was "not much at all". It might be many days before she can tell investigating officers what happened, given her serious condition, he said.