51 Tongan high school students have been released on bail but 22 remain in custody following last week's clash involving students from Tupou and Tonga Colleges.
Following the incident, which left a man in hospital in a critical condition, 147 students were arrested.
Police have described the rivalry between the colleges as a national crisis while others are calling for the government and churches to step in and end it.
About half of the 147 students were released from custody earlier this week and following a court appearance on Thursday, another 51 were released after being charged with trespass and wilful damage.
The 22 still in custody have been charged with trespass, housebreaking, causing grievous bodily harm and one student has been charged with attempt to commit arson, knowing it would be life threatening.
They are to appear in court on Monday.