Dunedin police expect to refer several teenagers to youth aid after a 15-year-old girl was assaulted on a city street yesterday.
High schools were helping police investigate after the girl was attacked while other teens, some filming on smartphones, watched on.
Police were called to the assault in View St, in central Dunedin, about 3.45pm yesterday.
The alleged attackers came from several high schools in the nearby area.
It is unclear what led to the incident or whether any footage from the attack circulated on social media.
Constable Paul Kennedy confirmed to RNZ some witnesses filmed the assault.
"[The] people involved didn't physically record anything, but with lots of school kids around at the time a couple of phones captured some footage," he said.
"Police are involved and will be speaking with all the girls in due course, their parents, and the various schools, as the people involved were from several different high schools.
"Police have liaised with one school already, they are taking the matter seriously and will be taking appropriate action."
The victim sustained minor injuries as a result of the assault.
Otago Girls' High School principal Linda Miller confirmed the school - which is close to where the incident took place - was investigating the matter.
"We have contacted all families and we are investigating," she said.
"This is something we are concerned about."
She had also spoken to the principal of one of the other schools involved.
She would not comment on what action had taken place so far, and said she would not comment further until the investigation had been completed.