A toddler has been killed in a police car chase in NSW.

A toddler, playing with her sisters in the backyard of her family home, has been killed after she was hit during a police chase involving a stolen car.

Police attempted to stop the car at Constitution Hill, near Parramatta, about 7:00pm last night before it sped down a street and ploughed into the back fence of the home in Bessbrook Way.

The stolen car ploughed through the back fence of a home in Bessbrook Way at Constitution Hill in Sydney’s west, during a police pursuit. (ABC News)

The driver of the stolen car kept driving through a nature strip before abandoning the vehicle.

A 23-year-old female passenger tried to flee but was arrested by police. The male driver of the stolen car remains on the run.

Assistant Commissioner Frank Mennili said it is not clear whether the offending car, or the police following, hit the girl.

“That is a role for the critical incident investigation team, that will look at all the matters involved in this particular operation,” he said.

The 17-month-old girl suffered critical injuries and was taken to The Children’s Hospital at Westmead where she later died.

Neighbours told the ABC they believed the girl was one of eight children.

Assistant Commissioner Mennili said the driver had a history of violence.

“We’re reaching out to members of the community. This person is well-known. They know who this person is,” he said.

“I must stress that we had specialist resources on the ground for this particular job because of the risk to the community.

“We were dealing with violent offenders, so we had to try to prevent these people from committing offences.

“Unfortunately, it’s a tragedy that’s occurred.”

The 23-year-old passenger from the stolen car is assisting police.

A critical incident team is now investigating the circumstances surrounding the incident, including the pursuit.

The investigation will be overseen by the Professional Standards Command.

This post originally appeared on ABC News and has been republished with permission.