Dunedin's supermarket attack could have been fatal, but for the quick work by first responders

Four people remain in Dunedin Hospital after being stabbed in the Cumberland St Countdown, on Monday afternoon.

All required surgery and are described by police as having a long road ahead.

Southern District Police Commander superintendent Paul Basham says the response by emergency staff and members of the public was brave.

He says feedback indicates the speedy response by first responders almost certainly saved the lives of some victims.

A 42-year-old man faces four charges of attempted murder and has been remanded in custody until his next court appearance in June.