Police hunting a gunman after a violent domestic attack in Hamilton last night say he is dangerous and should not be approached.

They said Colin Rangi Robyn Kiriona, a 25-year-old Maori, was known to have connections in both the Waikato and Wanganui areas.

Hamilton city area commander Inspector Rob Lindsay said the drama started when a woman fled a house in suburban Nawton and raised the alarm about 8.30pm yesterday.

"This person suffered a variety of serious assaults and was taken to Waikato Hospital," he said.

"She suffered serious physical injuries in her ordeal which required medical attention that is still ongoing.

"We are also aware that she was subjected to an alleged earlier assault where the offender held her against her will and a firearm was discharged two to three weeks ago."

The 31-year-old woman's two children, aged seven and three, were present in the home at the time of the incident.

Mr Lindsay said police cordoned off a Nawton home about 11am today looking for the offender.

"Distraction devices were used. However, no shots were fired and the offender was not located at the address, a search of the property is continuing and a scene guard is in place."

Mr Lindsay said Kiriona had gang connections and was considered dangerous.

Kiriona was 1.75m tall, of medium build and known to be using methamphetamine, he said. Kiriona was a patched gang member, and had a distinctive bulldog tattoo on the left side of his face.

Police said anyone knowing Kiriona's whereabouts or sighted him should contact them.