Canterbury Superintendent John Price reassured residents and the wider public that there was no threat to public safety.
"Experienced officers are working to establish the circumstances surrounding this tragic event.
"As a community, it is very important everyone cares and looks out for each other - especially in times of pressure and stress. We ask that people ring police or our partner agencies if they are experiencing this.''
One neighbour said a couple aged 60 to 70 years old lived in the house.
The neighbour, who has young children, was told by police to "stay inside" about 5am this morning.
"I am shocked and surprised something like this would happen to this family."
The pair often had family visiting the house, the woman said.
Another neighbour said she woke at 5.30am to two bangs, and watched out the window as SWAT officers with megaphones moved in.
It was "kind of scary, to be honest".
Her partner, a lighter sleeper, had woken up earlier to hear a lot of people outside.
Police had entered her neighbour's backyard and told her to stay inside with the lights off, the woman said.
She had never met the pair who lived in the house in four years living on the street. There had only been one incident over that time - a tyre being stolen off the back of her partner's car.
A police spokeswoman had earlier described the situation as a "firearms family harm incident".
'IT'S POLICE - YOUR HOUSE IS SURROUNDED'
A section of the road, outside the property, has been cordoned off and a blue tarpaulin covers the front gate.
Wairākei Rd resident Gary Fahey woke at 4am to the sound of police yelling through what he thought was a megaphone.
"They were yelling: 'It's police, turn on your lights and come outside, your house is surrounded by the Armed Offenders Squad'."
He then saw the street had been blocked off by police vehicles.
About 25 minutes later he heard two sounds ring out which he thought may have been gunshots or tear gas.
Fahey, who is temporarily living on the road said he understood the older couple had lived there "for years".
A neighbour, who said he knew the couple well, never had any issues with them. He heard police yelling "come out of the house" very loudly this morning.
He said a woman who lives in the house has been unwell for quite some time.
A worker at the Z Burnside petrol station nearby said she saw police officers putting down cones in front of Grahams Rd early this morning.
"I was coming in to work. It was just before 7 o'clock because that's when I started,'' she said.
Police officers will continue to carry out a scene examination today. Post mortem examinations will take place in the coming days.
Only the property remains cordoned off - the road is open.
- starnews.co.nz, Staff reporter
