The woman told Moungatonga the bus was turning into Wyllie Rd when the pedestrians were struck.
A reporter at the scene said a woman standing inside the cordon could be heard wailing and some at the scene were hugging.
A witness at the scene told the Herald the bodies of two people, which had been covered with a white sheet, lay in the middle of the road.
The bus was parked up on the side of the road as well.
"It looks like the bus has collected these people and now two are dead."
A man who lives nearby, Avin Prasad, said the bus involved was the number 380, a bright orange bus that travels to Auckland Airport and is also known as "The Airporter".
Prasad said he did not see the pedestrians, but steaming takeaway food was on the side of the road at the scene.
Senior Sergeant Pete Marriott confirmed the bus was travelling away from the airport and turned left up Wyllie Rd.
He said three passengers were on the bus at the time of the crash. They were not injured and were sent home.
The bus driver was being supported and would be taken home in due time, he said.
Marriott said the two men killed were locals.
"It is incredibly tragic that two people have lost their lives this evening who were just out for the evening and our thoughts are with families at this time," he said.
The two men appeared to be on the road at the time of the crash but it was too early to say exactly what had happened. The traffic lights were working when police arrived, he said.
Go Bus chief executive Calum Haslop said the company was co-operating fully with police to determine exactly what happened.
"Words cannot begin to express our sorrow to the families of those who lost their lives. Our thoughts and prayers are with them," he said.
"We are supporting the driver, who will understandably be stood down whilst the investigation is underway and their wellbeing is cared for.
"We will continue to assist and work with investigators."
A worker at a nearby Mobil service station said he could see the crash on his security cameras and it was "serious".
The worker said he could see emergency vehicles and crowds.
"It's too big ... [it looks] like a marathon. There's too many vehicles [stopped]."
A man working at the Chinese Choice Takeaways said a customer told him a bus had struck two men.
There were "heaps" of ambulances and police cars, he said.
The road is closed and diversions are in place on Puhinui Rd at Noel Burnside Rd and Vision Place, and on Wyllie Rd at Gifford Rd.
Motorists are being asked to avoid the area.