The arrests follow an armed manhunt in the Horowhenua District on Friday.
Manawatū area commander Inspector Ross Grantham said in the early hours of Thursday, four people entered a store on Oxford St and threatened the employee with a firearm.
The group took cigarettes and other items before fleeing the area in a vehicle.
Grantham said the employee was "thankfully uninjured" but was "understandably shaken by the incident".
He said as part of the investigation police, including the Armed Offenders Squad, conducted a search warrant at a Seddon St address on Friday.
Two men at the property were arrested without incident.
During the search warrant, a vehicle containing three people was seen exiting the driveway of a nearby "property of interest".
Grantham said police signalled the vehicle to stop, however the driver failed to stop and fled from police. A pursuit was abandoned due to the way they were driving, he added.
A short time later the vehicle was located abandoned on Macarthur St after the occupants fled on foot.
Police found a firearm and ammunition near the vehicle and, a short time later, a woman was taken into custody.
Later on Friday a man who had been spotted hiding in a nearby bush before getting into a vehicle by a member of the public, was taken into custody without incident.
Grantham said police are still searching for the remaining person and the investigation into the aggravated robbery was continuing.
Three men aged between 18 to 23 years appeared in the Levin District Court today on aggravated robbery charges, and a 32-year-old woman appeared in the Levin District Court on a firearms charge.
