Image released of man involved in Northland aggravated robbery

Photograph shows offender entering Hilltop Dairy at approximately 4.15pm last Tuesday. Photo / Supplied

An image has been released of the man involved in an aggravated robbery at a Northland dairy in which a shop assistant had a long-barrelled gun pointed at her.

Police have released a CCTV footage still in an appeal for the public to help identify the man.

A firearm-wielding robber stole cigarettes and cash from the Hilltop Dairy in Dargaville on Tuesday -- the fourth robbery in which cigarettes have been targeted in recent days.

The female proprietor, who was alone in the shop, was confronted by a man pointing a long barrelled firearm at her. The offender made off with an amount of cash and a number of packets of cigarettes before fleeing on foot.

Police said the 49-year-old victim wasn't physically hurt in the incident, but was traumatised and receiving support from Victim Support.

Police want to apprehend the man "to prevent any further violent crimes".

The offender, whose age is unknown, is of thin to medium build and about 1.7m to 1.8m tall.

He was wearing a grey coloured hooded sweatshirt, white peaked cap, sunglasses, grey long trousers and sports shoes. He possibly had a red bandanna around the lower part of his face and neck.

Police want to speak to two men that were seen near the dairy driving a beige or tan coloured twin-cab ute.

The robbery is the fourth targeting cigarettes in recent days, including a "vicious and callous" attack on a service station attendant in Levin who was stabbed in the head, face, and arm on Sunday.

In that incident, the offender, who obscured their face with a bandanna, stabbed the male attendant at Mobil Oxford St and stole cigarettes before fleeing the scene about 4.30am.

The attendant was recovering at Palmerston North Hospital from injuries that were not life threatening. A 21-year-old Levin man was arrested in relation to the incident.

On Saturday, a dairy owner was robbed at gunpoint at the Nancy Ave dairy in Mairehau, Christchurch.

The masked robber apparently waited until owner Bankhaj Patel's wife was alone in the shop before coming in with a gun.

"He pointed the gun to my wife, asked for ciggies and just walked away," Mr Patel said. The thief also made off with cash.

On Friday, three men, one armed with a screwdriver, robbed a liquor store in Taupo.

The group threatened the store worker and took off with money, cigarettes and alcohol.