Another 17-year-old boy was charged with disorderly behaviour and resisting arrest.
Two 15-year-old boys were referred to youth aid.
A principal of one of the schools, who cannot be identified due to Youth Court rules to protect young offenders, said one student had been expelled and two stood down.
He said the school had taken action against three students, and the matter was now with police.
Another principal said that no students had been punished, and another said it was against the school's policy to "comment to the media about individual student disciplinary issues".
A police spokeswoman said officers were still working to identify others involved. It was understood they were using CCTV footage and mobile phone recordings.