Two men have been taken to hospital in Coonamble after a crash involving a police car in the township this afternoon (Tuesday 20 May).

A Bathurst truck driver who witnessed the collision told the Western Plains App that the police vehicle was heading north on the Castlereagh Highway with its sirens on at around 1:30pm today when a white Mitsubishi utility made a U-turn from the oncoming lane near a petrol station.

The police car hit the passenger side and both cars ended up on the western side of the road.

The male drivers, the utility driver aged 68, were conscious after the crash and taken to hospital.

Neither vehicle had passengers. Police said both men suffered minor injuries.

The utility came to rest after hitting a corner of the back of a parked truck carrying two water tanks.

"Honestly, I didn't know how to react because I didn't know what had happened," the transport's driver Rowan Stocks said.

Damage to the police vehicle. IMAGE: River McCrossen

"I was just worried that someone had been hurt.

"I was on my phone. I could see it all happening in the rear vision mirror.

"It's done no damage to the truck."

He had come from Cobar to Coonamble on that day.

NSW Fire and Rescue and Coonamble Shire Council crews attended the scene and traffic began to return to normal by 2pm.

Police say they are investigating the cause of the crash.