Police said officers were searching the area for the alleged offenders.
Police are managing traffic while emergency services continue to work at the scene.
Hate Hone St John said one person had been taken to Middlemore Hospital in a serious condition.
An ambulance and rapid response unit were dispatched, a spokeswoman said.
Paramedics assessed and treated one person on the scene before taking them to hospital.
Fire and Emergency NZ was called to the area to help police and St John at 8.26am.
One fire crew from Māngere Fire Station and another from Papatoetoe responded, a spokesman said.
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