"[The driver] was just waving his arms, shouting and yelling. I'm fairly deaf and even I could hear all the commotion."
Clarkson went to get a medical professional from the nearby Tui Medical Centre, which was when the police were called.
Clarkson said he didn't think the students were in any immediate danger but noted they seemed shaken by the encounter.
"[The students] were standing there with their arms out, they couldn't work out what the hell was going on," he said.
Sheila, a receptionist at Whangārei Dermatology, saw the bus arrive just before 8am and noticed the driver was unsettled. "He was shouting and like banging on the steering wheel," she said.
Sheila then knocked on the driver's door to ask if he was okay. When he replied he was, Sheila then tapped on the window where there were about four schoolchildren, aged about 14, asking how they were.
Sheila said she didn't believe the children were in any immediate danger but said they looked unsettled.
"[The kids] just looked a bit concerned, they just didn't know what was going on."
After checking on the children, Sheila went to Tui Medical Centre to inform them, and then police arrived at the scene.
The driver of the vehicle was taken to hospital for a mental health assessment after he stopped en route to Whangārei Boys' High School and Whangārei Girls' High School and shut himself inside the bus with about four students.
A spokesman from bus company Ritchies said the driver was safe "and okay" following the incident.
The investigation was ongoing, with reports to police and the Ministry of Education.
A police spokesperson confirmed officers attended the incident on Maunu Rd in Whangārei after being called by someone worried about the bus driver.
"A small number of occupants who were on the bus have safely left the scene and the bus driver has been spoken to by police and is being medically assessed."
A nearby resident, who wished to remain anonymous, said police cars were parked at both ends of the bus when she first witnessed the incident.
"I noticed there was a plain cop car in front of it and two cop cars behind it. By the time we looked out there, the driver seemed to be sitting in the bus and within 20 minutes, an ambulance turned up and we know that there's regular school buses that stop there."
Two hours after the incident police were still in the process of identifying the schools attended by the students involved. Police were working with the pupils to offer support if required.
A senior staff member at a Whangārei secondary school said they first learned about the incident from the Ministry of Education, which was contacting schools to piece together yesterday morning's incident.
Kim Shannon, head of education infrastructure service at the Ministry of Education, said the agency was closely following Ritchies' investigation.
"Our local office staff have offered support to the schools whose students were on the bus at the time of the incident and will continue to be available as required."
