One confirmed dead, several school children injured in Sydney bus crash.

A man had died and five school children have been injured after a serious bus crash in northwest Sydney this morning.

The bus, which collided with a car just after 8am at the intersection of Londonderry Road and The Driftway in Londonderry, was reportedly transporting a group of children to school.

AAP reports the driver of the smaller vehicle has died, while two children have been taken to Nepean Hospital with minor injuries including head wounds.

Six were assessed by paramedics on site and the uninjured bus driver was taken to hospital for an assessment.

There has been some speculation the driver of the car was involved in a police chase prior to the accident, with the Sydney Morning Herald reporting skid marks were visible on the grass on the side of the road.

Channel 7 footage from the scene showed the wreckage of a  silver car at the side of the road, draped in a green cloth.

"We as parents can't praise the bus driver enough," one mother wrote online.

"His quick actions and the way he maneuvered that bus is what kept ... our son from serious injury today. I personally would like to not only thank him but hug him ... Thank you bus driver."

Police are currently investigating the incident and have appealed for anyone who saw the crash to contact Crime Stoppers on 1800 333 000.

Feature image: Nine News