Armed police have fired tear gas at a Christchurch house this evening, yelling for its occupant to "come on out" during a tense stand-off

Witnesses say armed police arrived at the Dunster St address at 4:50 this afternoon, with officers heading down a long driveway.

The wanted person is in a house in a back section and has closed the curtains.

A Police negotiator has been heard have calling out on a loudspeaker trying to entice the person they want out of the house.

Police have fired a number of tear gas canisters into the house, including through the back door.