A minibus full of students from a south Auckland tertiary education institute was shot at as it returned to campus after a field trip this afternoon.
The vehicle was carrying 15 people from Te Wananga o Aotearoa in Mangere, including students and teachers.
Police said it was travelling on State Highway 20 between Massey Rd and Puhinui Rd shortly after midday when a car entered the motorway at Massey Rd and drew up behind in the right-hand lane.
Passengers saw what they believed was a pistol pointed at the vehicle before a window shattered.
The minibus got off the motorway at Puhinui Rd.
No one on board was injured, but a spokesman for the wananga said they were shaken.
"Certainly it's a surprise. It's not something that we've ever experienced so I'd have to agree [that it was random],'' he said.
The organisation was focused on ensuring the well-being of its students, who were being offered victim support.
Some of the students were now back on campus, others were talking to police about what they saw.
The minibus was later towed away.
Police said initial indications were that the weapon was a BB gun and that the occupants of the bus were not specifically targeted.
Witness descriptions of the vehicle were unclear but police wanted to hear from anyone who saw a red or maroon car acting suspiciously in the area or who had any information about the incident.
Anyone with information was urged to contact Otahuhu police on (09) 259 1200 or Crimestoppers anonymously on 0800 555 111.