Two young children have died after a vehicle struck a pram in a devastating crash in Sydney’s south-west this afternoon.

Emergency services were called to the intersection of Joseph and Gilbert streets in Cabramatta about 3.15pm on Wednesday following reports of a collision involving a car and a pram.

Police said the children, both aged under five, were treated at the scene by NSW Ambulance paramedics before being taken to hospital in a critical condition. They later died in hospital.

A 33-year-old woman known to the children suffered minor injuries and was treated at the scene.

The driver, a 56-year-old man, was uninjured. He was arrested and taken to hospital for mandatory testing.

A crime scene has been established and detectives, with assistance from the Crash Investigation Unit, are investigating the circumstances surrounding the crash.

The children are yet to be formally identified.

Cumberland Highway remains closed southbound between Gilbert Street and Coventry Road as investigations continue.

A report will be prepared for the Coroner.