I heard the mum screaming and crying. People started coming outside, and they said there has been a shooting."

The long-time Punchbowl resident said she often waved to the victim's mother, who would sit out the front of her house, but she did not know the victim.

"It is not a nice thing to happen here. I've lived here for 30 years, and I've never had a problem worrying about anything like this," she said.

"It's hard to explain, people going crazy killing each other."

Superintendent McLean said the shooting was believed to be a targeted attack, and the public should not panic about random shootings.

He said there was nothing initially to suggest the shooting was linked to the shooting of Mr Eid, 38, who was a "cleanskin" with no known criminalhistory or links, but that would form part of the ongoing investigation.

In that shooting, Mr Eid, a father of four, was doing the tiling work on his, Punchbowl home with an electrician, Mohammed Hanouf, 34, on November 28 when two masked gunmen opened fire on them.

Mr Hanouf, also a father, managed to stumble to the front of the house where he collapsed in front of shocked neighbours. He survived the shooting.

Police also do not believe the latest fatal shooting is linked to separate drive-by shootings in Sydney on Tuesday.

Several rounds of bullets were fired at a home and a car in Cherrybrook in north-west Sydney about 5.30am, police said. Meanwhile, a single gunshot was fired from a vehicle at a home in Milperra just before 2am on Tuesday,