A person has been arrested after reports a stolen car hit a group of cyclists in Auckland, with five people hurt and a dog killed.

RNZ understands a man allegedly stole a car before he crashed into a group of cyclists. 

Emergency services were called to Manukau Rd in the suburb of  Epsom about  7.05am on Wednesday. 

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

Three were taken to hospital - one in critical condition, another with serious injuries and a third in a moderate condition.

Two other people were treated at the scene.

Several damaged vehicles were in the crash area. Photo: RNZ

Several smashed vehicles could be seen inside a police cordon, along with a crumpled bicycle next to a red puffer jacket.

Petrol station worker Manthan Patel said he heard a "crazy" sound before he witnessed a man driving a car crash into another vehicle.

He said the man then got out of the car and attacked a dog.

A staff member at Forbes Homemade Gourmet in Ranfurly Rd told RNZ she had seen the incident unfold. 

"There was a guy shouting in the streets next to where I'm working. It seemed as though he had no pants on."

She was worried that he could enter the workplace, so decided to call police.

Soon after, customers told cafe staff that the man had crashed a car and punched a woman, she said.

A cordon put in place around the area had caused "bumper to bumper traffic" in the area, but it was now clearing, she said.

Several smashed vehicles could be seen inside a police cordon. Photo: RNZ

Another witness told the New Zealand Herald they saw the man fighting with a woman at the intersection of Manukau Rd and Mt St John Ave, where he "threw punches", knocking the woman to the ground and stealing her keys.

After taking off in an old SUV and damaging nearby vehicles, the witness told the Herald the man drove into a group of cyclists "hitting one and sending them flying over the top of the car".

Another witness told the Herald he saw a man wandering around with "no pants, a T-shirt and scarf on".

A worker at Steam wand cafe just outside the Manukau Rd cordon said they heard a man screaming about 7am, followed by the screams of a woman. Police sped past the cafe soon after.

A cordon was in place in Manukau Rd between Ranfurly Rd and Queen Mary Ave. Photo: RNZ

Police have released limited information. However, a cordon is in place in Manukau Rd between Ranfurly Rd and Queen Mary Ave. Campbell Cres is closed to Puriri Dr. 

Drivers have contacted RNZ reporting a backlog of traffic in the area.

In an alert to passengers, Auckland Transport said buses are not stopping in the area at present.

In a post on X, MP for Epsom David Seymour said his thoughts were with those affected by the "horrible incident in our community".

"I will leave for police to communicate details of the incident, but there is no further danger since the one offender is in custody."

There would be an increased police presence in the area as inquiries continued.