Police Commissioner Howard Broad had contacted Ms Collins this morning to tell her police officers had been shot. However, she would not confirm reports that one was dead.
Ms Collins, who is in Queenstown at a police blue light conference, told NZPA the mood was sombre.
"I am extremely shocked and concerned. I'll be cancelling all my appointments tomorrow and moving straight to Napier to be with our police and their families," she said.
"I'm not going today ... because police are dealing with an extraordinarily difficult situation right now and I want to make sure that they are focused on that, not worrying about their minister getting in the way."