Two teenagers have been seriously injured after an 18-year-old ride-share driver allegedly ran them down on the New South Wales central coast.

The injured teenagers were part of a group who requested a local ride-share service about 3am on Sunday, police said.

However, police said when the group got inside the van the driver, who was allegedly under the influence of alcohol, began driving erratically, causing them to be thrown around inside.

The driver dropped the group of teens on Budgewoi Road, Noraville 20 minutes later, but when he drove off he allegedly did a U-turn and drove straight for the group, hitting two of them.

A 15-year-old boy was left with pelvis, leg and back injuries and was taken to John Hunter hospital in a serious but stable condition.

A 16-year-old girl was treated by paramedics for significant head injuries. She was transferred to Wyong hospital in a serious condition before being transferred to Royal North Shore hospital.

After the collision, the teenagers are alleged to have dragged the man from his van and assaulted him; he was taken to Wyong hospital with minor head injuries under police guard where he underwent mandatory blood and alcohol tests. The man was released from hospital on Sunday afternoon.

He was charged with multiple offences including dangerous driving occasioning grievous bodily harm, negligent driving occasioning grievous bodily harm, driving whilst suspended, and take and drive conveyance without consent of owner. He was refused bail and is due to appear before Wyong local court on Monday.