A toy gun was the catalyst for one of more than 100 callouts the Christchurch Armed Offenders Squad attended in the space of a year.
Figures released under the Official Information Act show armed offenders squads nationwide attended 915 callouts in the 2011-12 financial year, 108 in Christchurch.
The busiest squad was Wellington, with 146 callouts, followed by Auckland (116) and Christchurch.
The city's area commander Superintendent Andy McGregor said the AOS was deployed in emergency situations, particularly when firearms were believed to be involved in an incident, or where there was a risk that police face may face armed offenders.
The squad was deployed on average around twice a week, he said.
"A significant number of AOS callouts are pre-planned operations, where the squad provide support for drug warrants and similar deployments," he said yesterday.
"Other occasions where AOS has been deployed in the past year have included incidents such as domestic disputes, neighbour disputes, firearms being presented at vehicles or members of the public, and an incident at a high school involving what turned out to be a toy gun."
The squads were first established in 1964, after the fatal shooting of four police officers in incidents in Lower Hutt and Waitakere.
There are now 17 squads, covering all main centres.
The New Zealand Police website states, the basic methods of operating for the AOS are to cordon, contain and appeal to armed offenders.
Police say the tactics are successful in the vast majority of incidents - which are resolved without the use of force.
The AOS are also used for some pre-planned operations where a high risk is perceived - including large cash escorts and assisting other police with search warrants.
The squads are supported by negotiation teams and specially trained police dogs and handlers.