A terrified schoolgirl managed to wriggle free from the grip of a man who grabbed her as she headed to school.

Police are investigating following a report of the incident, between 9.10 and 9.30am on Thursday.

The girl, 15, was walking along an alleyway between Santos Place and Waitangi St in Onehunga when she was approached by a man she didn't know, a police spokeswoman said.

The girl was able to free herself.


"We will be speaking further with the victim next week and hope to be able to provide a fuller description of the offender and the incident after that," the spokeswoman said.

The girl's mother told Fairfax the man grabbed her daughter from behind while she was on her way to catch a bus and get to class. He told her to keep quiet but she got away.

The police spokeswoman said it was too soon to say if the incident was linked to other reported assaults of women in Onehunga.

Between October last year and March there were 11 street-grab style assaults against women aged 21 to 52 by a young man.

An arrest is yet to be made.