The pilot of a light plane had a laser light aimed at her while flying over Hamilton on Tuesday night.
Police say the pilot reported her aircraft was "painted"' by a powerful green laser light, just north of the city centre.
They say the pilot circled to try to pin-point the source of the laser and established it to be coming from somewhere in the vicinity of Fairfield College.
Patrols were sent to the area, but were unable to find those responsible.
Police say laser beams can cause momentary flash-blindness and have the potential to distract pilots.