An armed man is believed to be holed up inside a Hamilton house after a gunshot was heard following an incident involving the man's partner and young child.
The Armed Offenders Squad was called to the house - on Tomin Road in the suburb of Glenview - shortly after a shot was heard just after 9am.
Neighbours said they heard yelling, screaming and windows smashing before the shot was fired.
There were no reports of injuries.
Waikato police communications manager Andrew McAuley said the woman and child had left the property.
"Shortly after 9am there were reports of domestic incident in Tomin Rd in Glenview. We understand a shot has been fired. At this point in time there is an area cordoned off and a property under observation.
"We understand that there were three people in the property - a male, a female and a small child," Mr McAuley said.
"At this time the female and the child have made their way out of the house. The man is still believed to be in the house.
"The Waikato armed offenders squad is at the house along with significant numbers of the police and members of the Auckland and Waikato dog squads."
Neighbours said the couple, who are in their 40s, were long-term residents. The house has been in family for many years.
Residents have been pushed back from the scene and the Armed Offenders Squad were in position outside the house.
Police negotiators have arrived and the street was cordoned off.