"Along with victim support we're working hard to support the victims, their whānau and our staff," he said.
"We acknowledge this incident has the potential to be unsettling for our community and I want to reassure the residents that we are not looking for anyone else in relation to this matter.
"We are absolutely committed to ensuring that people in Whanganui are safe and feel safe and I can assure the community there is no ongoing risk to the public as a result of this incident."
Allan said because the matter was before the court he would not comment further on the incident or charges.
He said the incident "was dynamic to say the least".
Our staff who attended had a lot to deal with in a short space of time," Allan said.
"We absolutely appreciate the support of the public, particularly staff from Te Oranganui and staff from the medical centre there who've helped the victims.
"Not being there, but listening to the event [I'm] extraordinarily proud of our staff and how they managed their role there. Difficult scene, obviously you know where it is, it's a public place, so we got control of that scene and provided assistance to the victims as soon as we practically could."
Whanganui mayor Hamish McDouall said the incident was "a tragedy".
"[It] reinforces tired old hackneyed tropes about Whanganui, which as everybody who lives here knows aren't correct," he said.
"Nevertheless it's obviously an immense tragedy for the individuals."
Three of the five injured remain in a stable condition in Whanganui Hospital while two others have since been discharged.
On Tuesday a worker from medical centre Te Oranganui, who did not want to be named, said a colleague witnessed the stabbings.
Te Oranganui nurses and a doctor ran to the aid of the victims.
Neighbours were shocked that such an incident happened on what was a normally quiet street.
Ronald Buckley lives at Kowhai Court, two houses down on Wicksteed St, and said it was a shock given he didn't hear anything at the time.
"I came outside for a fag and what a surprise that was," he said.
"It was a bloody shock, actually. I came out and saw a whole lot of cop cars and thought 'holy shit, where did they come from'?"
"When I got there, there was one lying on the ground. It was a big girl. She'd been stabbed, it was bad."
The worker said two other people who had been stabbed were walking around.
"You could see it. He was holding his neck and blood was pouring out. On his back, you could see where he'd been cut.
"There was another lying down, she wasn't moving. She was an older lady."
Trev Kereopa, a resident in the share house next to the home under investigation, said his neighbours always seemed nice.
"They were alright, they'd mind their own business and I'd say hello to them I when I saw them," he said.
"I can't really tell you how many people lived there, all I knew was the mother and daughter.
The Whanganui Chronicle understands the incident stemmed from a dispute between two flats.
A source said the incident arose from an argument over "something relatively minor" between two flats who share the duplex on Wicksteed St.