The children involved in an alleged triple homicide in Rotorua were aged just 3 years and 11 months old.

Bay of Plenty acting district commander Inspector Logan Marsh said an investigation into the deaths of three people at a house in the suburb of Glenholme continued on Wednesday.

"We can now release the age of the two deceased young children. They were an 11-month-old and a three-year-old.

"Police are continuing to support the family following this traumatic incident."

Emergency services arrived at the home on High St shortly before 10.30pm on Monday, where they found the bodies of two young children along with a critically injured woman who died at the scene.

Police began a homicide investigation and a man aged in his early 20s appeared in the Rotorua District Court on Tuesday charged with assaulting a person in a family relationship.

The man and the victims were granted interim name suppression and he was remanded in custody until next month.

Marsh said police and other specialist teams remained at the property where a forensic examination was continuing. 

"Our team are working tirelessly and meticulously through a complex scene, so we can provide answers for those impacted.

"An investigation of this nature will take some time and we thank the community for their patience.

"Staff will continue to conduct additional reassurance patrols in the Glenholme area and wider community over the coming days."

On Wednesday morning, Rotorua mayor Tania Tapsell said the community was devastated by the news.

"We're really devastated about the triple homicide that's occurred here in Rotorua and especially in the Glenholme neighbourhood.”

She said “nice families” had lived there for generations and there were quite a lot of elderly people.

"This is a wonderful neighbourhood that we are just shaken to our core that this has happened in Rotorua and there continues to be a police presence as they complete their investigations.

"Unfortunately, we do know that there are two very young children involved in this incident, so our thoughts are with the victims and all those impacted."

Tapsell said her message to the community was to stay strong, look after one another and report things to police if they had concerns.

"We need to support each other, not only through this incident but also as we continue to deal with increased uncertainty."

A 79-year-old man who had lived on the street his whole life said he was in shock since learning what had happened.

The people living in the house seemed to have recently moved in, he said, and he had seen new children around the street.

As a hearse arrived, family members were seen hugging and crying outside the High St home on Tuesday evening.