Others described thinking one person had been nearly beaten to death, meanwhile, a tradesman questioned the response from police.
Francis Mann, a builder, said he made numerous reports to police about dodgy behaviour from the teenagers long before the brawl started.
Not only did he contact emergency services, Mann also contacted several Auckland high schools to alert them of their students' behaviour.
School staff reportedly told him it was not their responsibility, despite many being dressed in uniform, as the students were not at school.
"I was quite shocked at their response. I think the whole incident could have been avoided if there was earlier intervention."
However, inspector Shawn Rutene said the police response was effective and they had been monitoring the teenagers for some time.
Officers who witnessed under-aged drinking from the youths supervised disposal of the alcohol and quickly intervened when the fight started.
Police were on scene throughout the afternoon and still had a presence there today, Rutene said.
Meanwhile, the inspector confirmed police officers used pepper spray on one occasion which helped them contain the situation.
"Our staff are required to make decisions in challenging circumstances," Rutene said.
In this instance, we ... monitored the gathering via CCTV cameras, from the Eagle helicopter and on the ground with a visible Police presence."
The brawl was reportedly organised on Instagram and was just one of many upcoming brawls of students from the "dirty south" and "west Auckland".
A student who was there told the Herald it was meant to be a gathering of students from various schools to celebrate the end of the school year.
But some students from certain schools used the gathering to organise a massive fight, circulating messages through Instagram stories.
As students started arriving from noon an "atmosphere of violence" began to grow.
"There was a vast amount of students gathering and we heard swearing and people running," the student said.
Police clear the public out of Mission Bay and Selwyn Reserve in Auckland. Photo / Supplied "And among all this chaos were repeated gang and school gestures, commentary such as: 'We gonna f*** your school up'."
The student phoned 111 as "multiple fights" broke out all around them.
One student was grabbed by a group from one school, and punched on to the sand, before being kicked while they lay on the ground.
"The amount of kicks to the head, made us think that he was dead because of the way he was laying lifeless there, with blood all over his face.
"Glass bottles were thrown everywhere on the ground."
As many as 40 police officers were called to the scene. Photo / Supplied The student said police arrived and attempted to break up the fights, and eventually used pepper spray on the brawling students.
Different fights were taking place all over Mission Bay and police seemed unable to control it, they said.
Witnesses reported about 40 police officers descended on the scene to break up the fight around 3.30pm.
Eight youths were eventually arrested, one for assault. One person was taken to hospital with minor injuries.
They were all released without charge and would be dealt with by Police Youth Aid.
