A West Babylon man operating an unregistered off-road motorcycle on Nicolls Road in Deer Park was airlifted to Stony Brook University Hospital with a serious head injury after police said his dirt bike collided with a car Monday night.

The collision took place at 9:40 p.m.

advertisement | advertise on newsday

Suffolk County police said the car’s driver, Sukhminder Singh, 18, of Deer Park, was not injured.

Police said Singh was headed eastbound in his 2015 Mercedes-Benz when he attempted to make a left-hand turn onto Carlls Path — and was hit by the dirt bike, driven by Frank James, 21.

James was thrown from the motorcycle, police said, sustaining the head injury.

No one has been charged in the crash, though both vehicles were impounded and the investigation is continuing, police said.