Six women closed the shutters of a dairy before violently assaulting the shop attendant and stealing cash and cigarettes.
Police are trying to track down the women who, about 5.15pm on April 3, entered the Hari Superette on Puhinui Road and started to take items including cigarettes and cash.
Counties Manukau Police Detective Senior Sergeant Kevin McNaughton said two of the offenders closed the store by pulling the shutters down.
"The store attendant was punched and kicked repeatedly by one of the offenders suffering serious facial injuries," he said.
Police need the public's assistance to help identify those involved.
"This is absolutely appalling behaviour, and neither police or the Papatoetoe community will accept it. We ask anyone who may know who these offenders are to please come forward."
• Please contact Constable Fuipu'a Mariner on 09 261 1300 or leave an anonymous tip via Crimestoppers on 0800 555 111.