"Most of them, 70 per cent of them, were like schoolkids."
Inspector James McKay said police had received "a very positive response" from members of the public who had witnessed or had information about the fight.
"We are working through the information provided and making good progress towards identifying those responsible," he said.
"We know this incident has been unsettling for the community and I want to reassure residents that we are doing everything we can to hold those involved to account.
"Police will retain a visible police presence in Stokes Valley as we continue our investigation."
Police still want to hear from anyone who can assist the investigation but has not yet been in touch, particularly anyone who has CCTV cameras with coverage of the Delaney Park and George St areas.
Anyone with information can contact Hutt Valley Police on 04 560 2600. Information can also be provided anonymously via Crimestoppers on 0800 555 111.