A police spokeswoman said they were alerted to the incident, on Dipton St, just before 1pm.
Initial indications were that a firearm had been discharged.
An area of the street has been cordoned off and police are conducting a scene examination.
There are no reports of injury.
A reporter at the scene said police, some of them armed, had blocked off the street.
Their attention seemed to be focused on a house near the intersection with Stapleton St.
A nearby resident said she heard "two loud boom sounds" before police arrived.
She said there was gang activity in the area.
Police asked anyone with information to contact them.
A witness at the scene said it appeared police had raided a house on Dipton St. One man was seen being searched on a car.
A spokesman for St John said they were notified by police but stood down as they were not required.
- ODT reporters/NZ Herald
