A Street in the eastern suburb of Christchurch was blocked off by the police after a gunshot was heard and reported early Friday morning. Police found that a firearm was discharged on the street by a park in the suburb of Avonside.
There were no reported injuries, Senior Sergeant Paul Robertson said in a statement, adding further investigations are underway.
The police said after the incident all police officers were ordered to arm themselves to ensure the safety of the public and police officers, Xinhua news agency reported.
Police strengthened security nationwide after a gunman stormed two Christchurch mosques and killed at least 51 people in New Zealand's deadliest terrorist attacks on March 15.
Police nationwide carried guns following the attacks as the National Threat Level was raised to high. The threat level lowered from high to medium on April 17 when frontline police returned to their normal rules about gun carriage instead of carrying firearms routinely.