AUCKLAND, Sept 20 - Emergency services were called to the crash outside Westlake Girls' High School on Wairau Road about 8.30am on Wednesday.
Those hit were from Westlake Girls and Westlake Boys schools with one girl critically hurt and another seriously injured, police say.
Four of the injured students were taken to Auckland City Hospital, while the fifth was treated at the scene.
Westlake Girls communications manager Helen Davies said a number of students saw the crash occur and they were being provided with counselling.
"We have a very experienced counselling team and they are working with students and staff members to support anyone affected by this event," she said.
The families of the injured students have also been notified, she said.
Police said they were talking to the driver, who had remained at the scene following the crash.
Photographs from the site show a blue Nissan having struck a metal fence at the school and NZME reports witnesses earlier seeing a girl lying hurt on the road and the sound of wailing.
A section of the major road at the intersection of Forrest Hill Road was closed and cordons remained in place, police said.