Two women critical after collision with police car

A high-speed collision involving a police car and another vehicle has left two women critically injured in hospital.

The police car was travelling under lights and sirens when it collided with the women's Kia sedan at Prairie Vale Road, Bossley Park in Sydney's southwest at around 12:20pm on Sunday.

The collision caused both vehicles to leave the roadway, crash through a fence and strike two separate houses.

At the time of the crash the police vehicle was responding to a priority incident involving a child seen running on the roadway.

The driver of the Kia, a woman believed to be in her late 20s, was treated at the scene by paramedics before being taken to Westmead Hospital in a critical condition.

Her passenger – a woman believed to be aged in her early 50s - was taken to Liverpool Hospital in a critical condition.

Two male police officers, both constables aged 24, were taken to Liverpool Hospital for mandatory testing and treatment of minor injuries.

Following initial inquiries, a critical incident was declared to investigate the circumstances.