Police are attending what is believed to be an incident involving a weapon at a house in the Auckland suburb of Grey Lynn.
A witness told the Herald there are 12 police cars, an ambulance and the armed offenders squad at a group of houses on Great North Rd.
He said he saw police arrive at the group of homes and get out of their cars carrying guns.
Residents of other houses were told the leave their properties, the witness said.
A police spokesperson said officers received reports of a man acting aggressively towards other people before 2pm.
They were told he was making threats and in possession of a weapon, but not a firearm.
The spokesperson said the man has been found at a nearby address and police are trying to negotiate with him.