One witness told the Herald they saw a few police cars speed past their Tangimoana property chasing a black car.
The vehicle was spiked along State Highway 56 south of Palmerston North and the driver and passenger were arrested at the scene.
A 34-year-old man and a 19-year-old woman have been charged with two counts of aggravated robbery, unlawful possession of a firearm and unlawful taking of a motor vehicle.
They are due to appear in the Palmerston North District Court tomorrow.
Detective Inspector Craig Sherida said the firearm had been recovered. He could not rule out further charges being laid.
An internal investigation is also under way and Police have notified the Independent Police Conduct Authority of the incident.
Police want to reassure the wider Manawatu community that there is no risk to their general safety.