Four masked robbers wielding knives and screwdrivers robbed a Whangārei service station of cash before the sole attendant was able to lock himself in a room.
The robbery happened on Sunday night and the quartet rushed into the shop area of Z Kamo as a customer was leaving about 9.35pm.
Detective Constable Joseph Reuben said the four robbers had bandannas wrapped around their faces and the hoods of their sweatshirts over their heads.
The robbers demanded money and cigarettes and the sole attendant opened the tills but managed to slip away and lock himself in a staff cloakroom.
Once the quartet realised they would not be able to access the secure tobacco cabinets they fled on foot towards Wakelin St, which was also the direction they arrived from.
A police dog and handler were called but were not able to locate the robbers.
Reuben said officers were going through security camera footage but appealed to members of the public who may be able to help with the investigation.
Anyone with information that could lead to the identification of the four people involved can call Crimestoppers anonymously on 0800 555 111.