A man who was out on parole was arrested after shooting dead four men and wounding a woman in an hour-long rampage in the Australian city of Darwin.

Police did not reveal a motive for the shotgun attack, but ruled out terrorism.

It was Australia’s third mass shooting since the country introduced tough gun laws in response to a 1996 massacre in which a lone gunman armed with two semi-automatic assault rifles killed 35 people in Tasmania state. Mass shootings are usually defined as those resulting in at least four deaths excluding the shooter.

In the rampage, four men were killed and a woman was wounded at five places around Darwin, said Northern Territory Police Commissioner Reece Kershaw.

The 45-year-old suspect was released from prison on parole in January and was wearing an electronic monitoring bracelet, Mr Kershaw said. Police did not say why he had been in prison or whether the bracelet helped police arrest him.

“He is an individual who’s well known to police and has a number of interactions adverse with the police,” Mr Kershaw said.

The woman who was wounded did not have serious injuries, he said.

The Health Department had earlier said two people were taken to a hospital with gunshot wounds and both were in a stable condition.

Mr Kershaw said the man was arrested after he contacted a senior police officer. An Australian Broadcasting Corporation reporter said she saw police tackle and taser the gunman at a busy junction.

Mr Kershaw did not explain why the suspect was being held under police guard in a hospital. The suspect had yet to be charged.

Northern Territory Chief Minister Michael Gunner described the incident as an “incredibly difficult night”.

“This is not the Darwin we know,” Mr Gunner said. “This may be an event you prepare for, but this is never an event you want to respond to.”

Witnesses described the shooter using a pump action shotgun to fire multiple blasts at the Palms Hotel and Buffalo Club. A victim was killed at each. Mr Kershaw confirmed that the suspect was armed with a shotgun, but could not confirm what type.

Pump action shotguns have been virtually banned from private ownership in Australia along with other rapid-fire weapons under the country’s tough gun laws designed to prevent mass shootings.