image sourceGetty Imagesimage captionA file photo of a Lynnmall in Auckland

Police in New Zealand have shot dead a man after he entered an Auckland supermarket and stabbed multiple people.

Local reports say at least six people were injured, with one witness describing a scene of hysteria.

The witness told news outlet Stuff NZ that he saw an elderly man lying on the ground with a stab wound.

Videos online show panicked shoppers running out of the Countdown supermarket at LynnMall in New Lynn.

"Police can confirm that a man has entered a New Lynn supermarket and injured multiple people," local police said in a statement.

"Police have located the man and he has been shot. He has died at the scene. This incident is still unfolding at this time."

Local reports say out of the six patients taken to hospital, three are critical, one is in a serious condition and two are in moderate condition.

A spokeswoman said Prime Minister Jacinda Ardern is currently being briefed on the situation, with a press conference due to be held at 17:15 local time (05:15 GMT).

Countdown's general manger of safety, Kiri Hannifin said she was "devastated by what's taken place in our Lynnmall store. We will be supporting all of our LynnMall team… Countdown Lynnmall will be closed until further notice."

A witness, identified only as Tim, said it was a scene of mass hysteria with several people being attacked before the assailant was shot.

"[People were] running out, hysterically, just screaming, yelling, scared," he told Stuff NZ.