Police say pilots are being put at risk and have warned people about the dangers of pointing lasers at aircraft.
"Having a laser shot into your eyes does cause temporary blindness," Wellington area prevention manager Insp Wade Jennings told Newshub. "Obviously if we have pilots who can't see and then disorientated, they could potentially lose control of the aircraft."
On Tuesday, a man was remanded on bail after being accused of pointing a laser at the Christchurch Eagle helicopter.
The 44-year-old was charged with possessing a restricted weapon.
Police said a laser was pointed at the chopper on the first two nights of its five-week trial in Christchurch.
In Wellington, green beams have been shone into two training flights in the past week.
"If you ever see anyone attempting or thinking about using a laser - discourage them or call [the] police," Insp Jennings said.
Anyone with information about the laser strikes is urged to call police on 105. The incidents have been referred to the Civil Aviation Authority.
"The lasering of an aircraft is totally unacceptable behaviour and could serious harm," a post on the Canterbury police Facebook page said.