Police are still looking for the occupants of the car, and the firearm.
They said while the manhunt continued the community would see an increase in armed police.
"This is paramount for staff safety and assists our ability to respond to incidents such as these where Police officers are threatened with firearms," police said in a statement.
"If you saw this car and its occupants in the Napier area between 7am and midday we would ask that you contact us - any sighting may assist the investigation.
"If you have any information regarding the people responsible we also need contact from the public, either directly or via Crimestoppers on 0800 555 111."