New South Wales police are investigating the possibility an alleged shooting attack in Sydney’s south-west, which killed one man and injured four others, was linked to organised crime.

Det Supt Craig Middleton said that police believed the alleged incident in Canley Heights was “targeted” but said the motive remained “quite unclear” at this “very early” stage of the investigation.

Speaking to reporters outside Fairfield police station late on Wednesday morning, Middleton described the alleged attack as “brazen and violent”.

“We are aware of some organised crime links although I can’t confirm that at this stage,” he said.

“I can also confirm that we believe that this is a targeted attack, although the motive for this attack is unclear at this stage and we’re working through a number of inquiries.”

Middleton said all five of the alleged victims knew each other.

He did not confirm many details of how detectives believed the alleged incident transpired, but said police were looking for two men who entered a home on Arbutus Street, Canley Heights before “a number of gunshots” were allegedly heard.

“They fled that premises and decamped in a vehicle that has not been recovered by police at this stage,” Middleton said.

Police set up a crime scene at the home after the men self-presented to two nearby hospitals.

A 28-year-old and a 32-year-old arrived at Liverpool hospital at about 8.30pm on Tuesday with multiple wounds.

While the younger man was treated for a gunshot injury, he died a short time later.

The 32-year-old was still in hospital on Wednesday morning with a neck injury and remained in a serious but stable condition.

At about 8.40pm on Tuesday, two other men – a 23-year-old and a 22-year-old – presented to Fairfield hospital in serious conditions before being moved to other hospitals for further treatment.

The 23-year-old received care for a gunshot wound to the neck and the other was treated for a shoulder injury.

The fifth man, a 19-year-old, arrived at Liverpool hospital about an hour later with injuries to his arm, and remained in a stable condition on Wednesday.

“Initial information indicates the men were all injured during a shooting at the home earlier in the night,” NSW police said in a statement.

Officers were seen swarming around the hospitals’ emergency wards in the late hours of the night as an investigation was launched into the incident.