Two young children have died after being struck by a car in Sydney’s south-west.

A man who was allegedly driving the car involved has also been arrested following the horror incident on Wednesday afternoon.

First responders rushed to the intersection of Joseph and Gilbert Street in Cabramatta about 3.15pm after reports of a crash.

Upon arrival, Fairfield City Police Area Command officers found that two children under the age of five had been “struck by a car while seated in a pram,” NSW Police said in a statement.

The children were treated by paramedics before being transported to hospital in a critical condition.

Police later revealed the children had died.

The pair are yet to be formally identified.

A 33-year-old who is known to the children also suffered minor injuries and was treated by paramedics at the scene.

A 56-year-old uninjured man who was allegedly behind the wheel of the car was arrested and taken to hospital for mandatory testing.

A crime scene has been set up at the scene of the crash and officers from the Crash Investigation Unit are investigating the incident.

A report will be prepared for the Coroner.

Part of the Cumberland Highway at Cabramatta has been closed for southbound traffic following the crash.

As inquiries into the crash continue, police are urging anyone with information about the incident to contact Crime Stoppers via 1800 333 000 or nsw.crimestoppers.com.au.