The accidents happened on Nelson Bay Road, Williamtown, and Wollombi Road, near Millfield, police said.

The Williamtown incident, a head-on crash involving three vehicles near Newcastle Airport, happened about 1.45pm.

Police said a Nissan sedan travelling north and a Toyota station wagon travelling south collided.

‘‘A southbound four-wheel-drive was also involved in the collision,’’ police said.

A man in the Toyota was rushed to John Hunter Hospital and declared dead shortly after arrival, police said.

Several of the other people involved in the accident were taken to John Hunter Hospital.

In a separate incident, a female driver, 32, and boy, 10, of Cessnock, suffered serious injuries in a Wollombi Road crash, about five kilometres west of Millfield.

Police allege an eastbound police vehicle detected a Mitsubishi Lancer sedan travelling west at 130km/h in an 80km/h zone, about 1.45pm.

‘‘The Lancer then left the roadway and hit a tree,’’ police said.

The police vehicle ‘‘turned around and went to the crash scene’’ where officers tried to help three people who had been travelling in the vehicle.

Central Hunter Police Inspector duty officer Brian Tracey said last night police were conducting routine highway patrol speed checks when the accident happened.

‘‘There certainly was not a pursuit,’’ Inspector Tracey said.

The woman was flown to Royal North Shore Hospital and the child to Sydney Children’s Hospital at Randwick, which said last night the boy was listed in a serious but stable condition.