A woman is dead, and a man's critically injured, following a double police shooting in the Christchurch suburb of Bryndwr

Officers were called to Clyde Road after 11pm - to a man armed with a knife, threatening to hurt himself and his partner.

The man was shot and injured, with police fearing he was going to harm his partner.

The woman was shot after picking up the knife, and threatening police.

Canterbury District Commander, Superintendent Tony Hill says it's a difficult and distressing situation.

A critical incident investigation into the incident is under way