Motorists were asked to avoid the area and expect delays.
A Fire and Emergency spokesperson said they were in attendance at a motor vehicle incident and one person was trapped.
A Hato Hone St John ambulance spokesperson said they were notified of a motor vehicle incident in Warkworth at 4.02pm and responded with three ambulances and one helicopter.
“We assessed and treated four patients; one in a critical condition airlifted to Auckland hospital, two in a serious condition and one in a moderate condition transported to Auckland hospital by road.”