The gunman at the centre of a fatal shooting and hostage situation in Sydney has been pronounced dead at the scene. Police say they believe he turned the gun on himself.
Police freed three hostages at around 5pm (local time). Medics treated the hostages at the scene but it is understood they were uninjured.
Along with the gunman, a 43-year-old man died at the scene and two victims were hospitalised after being shot, Detective Inspector Mark Brett confirmed.
One is undergoing emergency surgery and the other has suffered superficial wounds to his lower body. Det Insp Brett described the situation is "delicate".
Police responded to reports of shots fired at 10:45am on Heald Rd at Inline Signs, a printing and signage business. It's thought the incident stemmed from a business dispute.
One man was shot dead in the driveway and two others were injured before the gunman barricaded himself in the building, taking hostages with him.
Roadblocks were set up and the public were warned to stay away.
Some local workers were taken to safety, while others were forced to take shelter inside surrounding buildings.
The heavily-armed 'BearCat' police vehicle was brought in and a large number of ambulances were also lined up outside the Inline Signs building.
The BearCat is a bullet and blast resistant vehicle that police have used in previous sieges.
At one point police units were pressed right up against the glass of the business, before taking a safer position behind several parked vehicles.
An employee of Konecranes said police had told them to stay inside their building while an operation was under way across the street.
"We heard five shots. There have been plenty of police and ambulances," said the woman, who wanted to remain anonymous.
"We have been told to stay indoors and away from the windows."
Another witness said SWAT teams had completely surrounded the building.
After a terrifying six hours, three hostages were freed. Police say they found a man's body when they searched the body, and they believe he died of a self-inflicted gunshot wound.
Inline Signs is a second generation family owned business formed in the 1970s.
Three of the victims are believed to be brothers.