Hamilton police are not ruling out the possibility of a link between three aggravated robberies in the city in a week.
In the latest, two men pointed a sawn-off shotgun at a staff member at an industrial supply store on Lincoln Street in the suburb of Frankton just before 4pm on Tuesday.
Police say no shots were fired and the men left empty handed.
On Saturday night, a liquor store owner was shot in the shoulder and hit on the head with a hammer as two men robbed his shop. He is still recovering in Waikato Hospital.
And on Thursday, a shotgun was fired into the floor during a robbery of a dairy after the shop owner struggled with one of two assailants.
In the first two robberies, both offenders wore balaclavas and the police say there were other similarities, but refused to link the two.
The description on the men in Tuesday's hold-up is different from the previous two robberies, but police say they are keeping an open mind about any link.