Christchurch's Richmond is the scene of an operation involving armed officers and police dogs

Reporter Claire Sherwood says about a dozen armed offenders squad officers, dressed head-to-toe in black riot-type gear, have rushed into a property.

A witness also says there are at least 12 police cars lining North Avon, McLeod, and Avalon Street in Richmond, where police appear to be trying to force their way into a home.

Locals have gathered to watch from outside the cordons, and neighbours say they heard screaming from the home last night.