Police have arrested two more people over an armed robbery of a dairy in the south Auckland suburb of Mangere.
The two men, aged 15 and 18, have been charged with aggravated robbery.
Two other men, aged 17 and 20, were arrested earlier.
All four men will now appear in the Manukau District Court today.
During the robbery a worker suffered facial and head injuries when he was punched and kicked, at the Kingsford Supermarket, about 7.30pm on Tuesday.
Inspector Fa'amanuia Va'aelua, who headed the inquiry, said direct appeals to the community helped lead to the first two arrests.
He said one man contacted police, and a second man was arrested overnight.
The first person contacted police after seeing publicity about the case, Inspector Fa'amanuia Va'aelua said.
"They saw it, they saw the media releases and they decided the best thing to do was contact police, and they did that."
Mr Va'aelua said police were looking for two more people, and he was confident they will find at least one of them before the end of the day.
He said preventing these things from happening required a co-operation between police and communities. "And that mainly is around families and youth."