Counties Manukau south area prevention manager Matt Hoyes said police understood the incident might be upsetting for people in the community.
"We are working hard to understand what has occurred and to locate all involved.
"Enquiries are in the very early stages and at this stage it has not been established as to whether the incident is associated with ongoing gang tensions across Tāmaki Makaurau."
Hoyes said an increased police presence in the area could be expected as police continued to investigate the incident and hold those involved to account.
The police spokesperson said motorists and the public should avoid the area as there are cordons in place.
Police and ambulance staff at the scene in Papakura. Photo / Ben Fisher
St John said one person in critical condition had been transported to Middlemore Hospital.
One ambulance and two rapid response vehicles were sent to the scene.
A spokesperson from the Unichem pharmacy across the road from the courthouse said they saw a man lying on the street just before 1pm, covered with a thermal blanket.
After customers started reporting to them that the man had been shot, surrounding shop managers attempted to question police and ask if they were safe.
They claim police made no attempt to reach out to the surrounding businesses to inform them of the road closure or incident.
Anyone with information can contact Police on 105. Crime Stoppers can be contacted anonymously on 0800 555 111.