Armed police at the scene where a man held two children hostage with a machete, before being shot and killed when officers entered the house.

Police had no other option but to shoot dead a man who was holding children hostage with a machete in Tauranga, the region's commander says.

More details have come to light about the dramatic and prolonged stand-off involving the man, a woman and three young children, which came to a violent end on Sunday afternoon.

Bay of Plenty police district commander Andy McGregor defended the actions of officers at the scene during a press conference in the wake of the shooting.

SUNLIVE Police entered the property soon after 3pm.

"It's sad, but there's no other option, we had to get those kids out of that house safely."

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Police rushed to the property in Oriana Cres, Bellevue, Tauranga, shortly after midnight following a call from a woman who said she'd been threatened with a knife.

Officers entered the home and found the offender holding a machete to a young child, McGregor said.

"He threatened to harm that child if the police did not leave the address."

Police retreated, managing to take one of the young children at the home with them, he said.

As officers established a cordon, the Armed Offenders Squad and a negotiating team were called in.

"The police negotiating team tried everything to resolve this situation peacefully," McGregor said.

However, police received medical advice that afternoon raising serious concerns over the safety of the children.

That was due to their very young age, dehydration, a lack of food and the stifling heat on the first floor of the building where they were being held.

Police decided to enter the property and did so just before 3pm, McGregor said.

"On entry at the address the offender had a knife at one of the child's chest, he was then shot. He died shortly after."

The two children still inside were evacuated from the property safely.

Two of them, aged four and six, have been taken to hospital - the third is aged 11.

"This is a very traumatic event for them and it's something that no one should ever have to go through and we're offering them support at the moment.

"This is also very traumatic for our own staff. But in the end we've got two children that are out safely."

McGregor said the number of shots fired, reported to be numerous based on a video account, would be part of the investigation.

The officers involved would be on a mandatory 10-day stand down, McGregor said.

"I'm satisfied they did the right thing."

The incident would be referred to both the Independent Police Conduct Authority, as is standard after police shootings, as well as the coroner.

The man was known to the police, McGregor said.

A full scene examination of the property would begin on Monday morning.

Police Minister Stuart Nash has offered his sympathies to the family of the man shot dead.

"It is appropriate that independent external agencies, including the IPCA and Coroner, will examine the circumstances of the death, and I will not comment on the details of today's shooting," Nash said.

"My sympathies and condolences go out to the man's family. I also recognise how frightening the last few hours have been for the woman and children caught up in this traumatic incident.

"They will receive support from police to help them with the days, weeks and months ahead.

"It is important to also acknowledge the distressing impact this shooting will have on the officers involved. We trust Police to make the best decisions in extreme situations. Police put themselves in harm's way in order to keep the public safe. This will stay with them.

"I encourage the officers and other Police staff to take advantage of all the support and assistance available to them to help deal with the today's events," Nash said.

According to the Homicide Report, the incident is at least the 21st fatal police shooting since January 1, 2004.