MELBOURNE, Australia

A gunman who reportedly killed one man and wounded two others Monday at an industrial complex in Sydney has died from a self-inflicted wound, according to Australian police.

News broadcaster ABC quoted a detective inspector from Macquarie Fields Local Area Command saying that specialist police entered the building six hours after the gunman shot the three men, and discovered three factory workers hiding.

Mark Brett had earlier told a press conference that a 43-year-old victim had been killed, while two other men who sustained gunshot wounds were transported to a nearby hospital.

"One is undergoing emergency surgery, the other has superficial wounds to the lower part of his body," he said.

The ABC quoted an unnamed Liverpool Hospital spokesperson saying the wounded were both in a stable condition.

Police later said they could not confirm when the 33-year-old suspect, armed with a long-armed weapon, had shot himself and an investigation into the motive behind the incident is ongoing.

The incident is not believed to be terror-related.

According to The Sydney Morning Herald, the three victims were brothers, and the violence is believed to have resulted from a business dispute between them and the gunman -- reportedly a member of the Finks outlaw motorcycle club.

One man was reportedly arrested at the scene for allegedly hindering police.

A tactical operations unit, negotiators and paramedics had surrounded the evacuated area.

An employee at an entertainment agency located around 50 meters (165 feet) from the unit where the violent broke out told ABC that the entire area had been placed under lockdown.

"My colleague actually left to go and get the boss a cake for his birthday and the police came screaming in the vehicles and just told everyone to get back inside their factories," Rogan Burns said.

In Dec. 2014, Sydney had been shaken by violence during morning rush hour when a gunman laid siege to a cafe where 18 people were held captive for 16 hours, leaving three people -- including the captor -- dead.