Key Points:

An Auckland schoolgirl may have been thrown from a minibus and then dragged underneath it when it crashed carrying 11 students on a Coromandel road during a school camp.

The girl has serious leg injuries and was first taken to Thames Hospital and then transferred to Waikato Hospital after the van crash this morning.

Two other minibuses from Glenfield Intermediate were travelling in convoy when the minibus crashed on Hikuai Settlement Rd leading to the holiday settlement of Pauanui.

The other 10 students and the driver were also taken to Thames Hospital with cuts and bruises.

The Year 8 school camp has been cancelled, the remaining students taken home, and two more Year 8 camps planned for coming weeks cancelled.

One of the first on the scene for emergency services was volunteer firefighter Steve Taylor.

The girl had been trapped but was freed before they arrived, he told National Radio.

"She was pretty distraught, obviously, because she had some quite bad injuries to her left leg."

Mr Taylor said it appeared the girl had been thrown from the van and dragged for some distance.

"I don't think she's got those injuries inside the van."

Both the girl and the driver were in shock.

Mr Taylor said the stretch of road could be dangerous in rain and warning signs were required.

"We do go to probably... two or three accidents a year there with cars rolling over right there. The corner has got the wrong camber on it and after a bit of rain it can be quite slippery."

Glenfield board chairman Steven Duxfield said principal Raewyn Matthys-Morris had driven to hospital to be with the most seriously injured girl until her parents arrived.

Mr Duxfield said other children at the camp but not in the crash had received support from staff.

The school camp has been cancelled and the students are to return home.

"The decision has been made to close the camp and the children should be back at home by the end of today.

"Until we receive a full report from the police following their investigation, the camps planned for the next two weeks have been cancelled."

He said the school board had full confidence in the school staff and outdoor education company that runs the camp.

The school had been in contact with all parents of children at the camp.