Commissioner returning to NZ over shooting

New Zealand's police commissioner is flying home as an armed stand-off - in which four police officers were shot - continues in the Bay of Plenty.

Mike Bush had only just landed in Australia on Wednesday when he was briefed on the incident, and will return overnight.

A no-fly zone is in place around the rural property where a sole shooter is surrounded by police.

Four police officers were shot on Wednesday in an effort to arrest a person taking shots at a police aircraft.

A large-scale operation is taking place at the property in Otakiri, about 70km from Rotorua.

The New Zealand Defence Force has sent a tactical lift helicopter and three light armoured vehicles to assist police.

Deputy Commissioner Mike Clement told reporters on Wednesday evening the stand-off started in the morning when shots were fired at a police aircraft on a cannabis operation.

Police closed in on the offender's property, but by 4pm three officers had been shot.

Two of the officers were taken to Whakatane Hospital in a stable condition, and a third is in Rotorua Hospital in a serious but stable condition.

A fourth officer was later shot in the hand, and has received medical treatment.

All officers were male, but Mr Clement would not confirm ages or the details of injuries.