AUCKLAND, May 19 - Police say the girls were followed by a man in a white van on Broadhaven Avenue and the man approached them on Radiata Avenue and asked them to get in the van. It happened between 8.30am and 9am on Friday.

The students did the right thing by refusing the man's demands and telling school staff, police said.

Principal Ross Willocks says the man was about 30- to 40-years-old, Maori, with tattoos on his face, including one possibly of a flame.

"This person was driving a white van (no windows on the side). The van had a black stripe along both sides with the letter K in the middle," he said in a post on Facebook.

The Ministry of Education has been contacted and a trauma specialist was on the way to the school, it said.

Police say the man was wearing a black t-shirt and black cap with white writing. The blue and green "flame" tattoo was on the side of his face.

He was described as having a very loud voice and there was no-one else in the vehicle.

Police are asking for people with information and witnesses to come forward and want any camera footage of the area at the time.