A driver is under police guard in hospital after a chase ended in a Western Sydney smash.

The 28-year-old man was pursued in an allegedly stolen car spotted on the M4 Motorway about 8.50pm on Friday.

Highway officers tried to pull the man over, but he allegedly failed to stop, and was chased to Reservoir Rd at Blacktown where the pursuit was terminated, NSW Police said.

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“A short time later, the vehicle crashed into another vehicle further along on Reservoir Rd,” police said.

The 28-year-old man was found trapped in the wreckage when emergency services arrived at the crash.

He was freed from the vehicle and taken to hospital with minor injuries.

The driver of the other car involved in the crash, a 25-year-old man, was also treated for minor injuries and taken to hospital.

No charges have been laid at this stage.

Investigations into the crash are ongoing.