Auckland Grammar School 'devastated' after student cyclists hit by stolen car

The headmaster of Auckland Grammar School says they are "devasted" after a group of students was hit by a car while cycling in Epsom.

A man was arrested after allegedly hitting the teenagers in a stolen car and strangling a dog to death on a busy street in the Auckland suburb on Wednesday morning.

Three Auckland Grammar School students were taken to hospital, one with life-threatening injuries.

Headmaster Tim O'Connor said the students were returning from cycling training.

"Our immediate priority is the health, safety, and well-being of the affected students and their families. We are also ensuring that counselling and support services are made available to members of our wider school community who have been impacted by this incident," he said in a statement.

He said the school was cooperating with the police investigation into the incident.

"Our thoughts are with the boys and families affected. Out of respect for their privacy, we will not be making any further comment at this time."

Auckland City District Commander Superintendent Sunny Patel said there was no ongoing risk to the community, but one of the teen boys was in a critical condition in hospital and had undergone surgery.

The two other boys were in a serious and moderate condition in hospital.

The teenagers had been training as part of a cycling club, he said.

Police were called to reports of a serious assault at the intersection of Ranfurly Rd and Manukau Rd about 7am.

A man without warning had assaulted a woman, causing bruising to her face, head and upper body, police said.

The offender fled in the stolen vehicle, hitting several vehicles before striking three cyclists who were riding on Manukau Road.

After crashing the vehicle, the offender approached a woman walking her dogs.

He strangled one of the dogs and it died at the scene.

Police were able to taser the man and pull him off the dog which had been killed.

Five patients were at the scene when Hato Hone St John arrived, a spokesperson confirmed.

The man was in police custody and Patel said charges would soon follow.